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Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Parametric time?frequency estimation of prosthetic heart valve sounds  

Science Conference Proceedings (OSTI)

Prosthetic heart valves have been responsible for extending the life spans and improving the quality of life of many people with serious heart conditions. Even though the heart valves are extremely reliable

D. E. Perkins; G. H. Thomas; G. A. Clark

1998-01-01T23:59:59.000Z

2

Investigation of a rotary valving system with variable valve timing for internal combustion engines: Final technical report  

DOE Green Energy (OSTI)

The objective of the program was to provide a functional demonstration of the Hansen Rotary Valving System with Variable Valve timing (HRVS/VVT), capable of throttleless inlet charge control, as an alternative to conventional poppet-valves for use in spark ignited internal combustion engines. The goal of this new technology is to secure benefits in fuel economy, broadened torque band, vibration reduction, and overhaul accessibility. Additionally, use of the variable valve timing capability to vary the effective compression ratio is expected to improve multi-fuel tolerance and efficiency. Efforts directed at the design of HRVS components proved to be far more extensive than had been anticipated, ultimately requiring that proof-trial design/development work be performed. Although both time and funds were exhausted before optical or ion-probe types of in-cylinder investigation could be undertaken, a great deal of laboratory data was acquired during the course of the design/development work. This laboratory data is the basis for the information presented in this Final Report.

Cross, P.C.; Hansen, C.N.

1994-11-18T23:59:59.000Z

3

Internal combustion engine with rotary valve assembly having variable intake valve timing  

DOE Patents (OSTI)

An internal combustion engine has rotary valves associated with movable shutters operable to vary the closing of intake air/fuel port sections to obtain peak volumetric efficiency over the entire range of speed of the engine. The shutters are moved automatically by a control mechanism that is responsive to the RPM of the engine. A foot-operated lever associated with the control mechanism is also used to move the shutters between their open and closed positions.

Hansen, Craig N. (Eden Prairie, MN); Cross, Paul C. (Shorewood, MN)

1995-01-01T23:59:59.000Z

4

Control vector optimal structure for minimal-time networks optimization  

Science Conference Proceedings (OSTI)

The methodology for the electronic networks optimization was elaborated by means of the optimal control theory approach. In this case the problem of the electronic system design is formulated as a classical problem of functional minimization of the optimal ... Keywords: Lyapunov function, circuit optimization, control theory application, minimal-time system design

Alexander Zemliak; Miguel Torres; Antonio Michua

2010-01-01T23:59:59.000Z

5

Closed-loop, variable-valve-timing control of a controlled-auto-ignition engine  

E-Print Network (OSTI)

The objective of this study was to develop a closed-loop controller for use on a Controlled-Auto- Ignition (CAI) / Spark-Ignition (SI) mixed mode engine equipped with a variable-valve-timing (VVT) mechanism. The controller ...

Matthews, Jeffrey A., 1970-

2004-01-01T23:59:59.000Z

6

Time O®set Optimization in Digital Broadcasting - Optimization Online  

E-Print Network (OSTI)

height, polarization (horizontal/vertical) and antenna diagram (directivity). In Figure 1 the time ..... Phase 2: Optimization and constraint generation continue =

7

Time-optimal Control of Spin Systems  

E-Print Network (OSTI)

The paper discusses various aspects of time-optimal control of quantum spin systems, modelled as right-invariant systems on a compact Lie group G. The main results are the reduction of such a system to an equivalent system on a homogeneous space G/H, and the explicit determination of optimal trajectories on G/H in the case where G/H is a Riemannian symmetric space. These results are mainly obtained by using methods from Lie theory and geometric control.

Jan Swoboda

2006-01-19T23:59:59.000Z

8

Optimal, real-time control--colliders  

Science Conference Proceedings (OSTI)

With reasonable definitions, optimal control is possible for both classical and quantal systems with new approaches called PISC(Parallel) and NISC(Neural) from analogy with RISC (Reduced Instruction Set Computing). If control equals interaction, observation and comparison to some figure of merit with interaction via external fields, then optimization comes from varying these fields to give design or operating goals. Structural stability can then give us tolerance and design constraints. But simulations use simplified models, are not in real-time and assume fixed or stationary conditions, so optimal control goes far beyond convergence rates of algorithms. It is inseparable from design and this has many implications for colliders. 12 refs., 3 figs.

Spencer, J.E.

1991-05-01T23:59:59.000Z

9

Combustion, Control, and Fuel Effects in a Spark Assisted HCCI Engine Equipped with Variable Valve Timing  

SciTech Connect

Widespread implementation of homogeneous charge compression ignition (HCCI) engines is presently hindered by stability, control, and load range issues. Although the operable HCCI speed/load range is expanding, it is likely that the initial HCCI engines will rely on conventional combustion for part of the operating cycle. In the present study, we have investigated the role of fuel properties and chemistry on the operation of a spark-assisted gasoline HCCI engine. The engine employed is a single cylinder, 500 cc, port fuel injected research engine, operating near lambda = 1.0 and equipped with hydraulic variable valve actuation. HCCI is initiated by early exhaust valve closing to retain exhaust in the cylinder, thereby increasing the cylinder gas temperature. This is also referred to as a 'negative overlap' strategy. A total of 10 custom blended gasolines and three different batches of indolene from two suppliers were run at 5 speed-load combinations and performance was characterized by timing sweeps. Within the quality of the data set, we can say the all fuels provided equivalent combustion and performance characteristics when compared at the same combustion phasing. The fuels did, however, require different degrees of retained exhaust as measured by exhaust valve closing angle to achieve the same combustion phasing. Fuels with higher octane sensitivity were found to ignite more easily or more quickly and to burn more quickly than fuels with lower octane sensitivity. This is an expected result since the engine is naturally aspirated and operates with high compression temperatures due to the high retained exhaust fraction and recompression.

Bunting, Bruce G [ORNL

2006-01-01T23:59:59.000Z

10

System for detecting operating errors in a variable valve timing engine using pressure sensors  

SciTech Connect

A method and control module includes a pressure sensor data comparison module that compares measured pressure volume signal segments to ideal pressure volume segments. A valve actuation hardware remedy module performs a hardware remedy in response to comparing the measured pressure volume signal segments to the ideal pressure volume segments when a valve actuation hardware failure is detected.

Wiles, Matthew A.; Marriot, Craig D

2013-07-02T23:59:59.000Z

11

Safety valve  

SciTech Connect

The safety valve contains a resilient gland to be held between a valve seat and a valve member and is secured to the valve member by a sleeve surrounding the end of the valve member adjacent to the valve seat. The sleeve is movable relative to the valve member through a limited axial distance and a gap exists between said valve member and said sleeve.

Bergman, Ulf C. (Malmoe, SE)

1984-01-01T23:59:59.000Z

12

Optimal Real-time Dispatch for Integrated Energy Systems  

E-Print Network (OSTI)

and HVAC operations. A real-time optimization program suchHVAC IES ISO-NE LBNL MILP NOx NP NRC NREL OLS P&DC PJM PUCT PURPA PV RETScreen RReDC Hybrid OptimizationHVAC equipment and other building energy equipment. This research is similar to the IES dispatch optimization

Firestone, Ryan Michael

2007-01-01T23:59:59.000Z

13

Time optimal software pipelining of loops with control flows  

Science Conference Proceedings (OSTI)

Software pipelining is widely used as a compiler optimization technique to achieve high performance in machines that exploit instruction-level parallelism. However, surprisingly, there have been few theoretical or empirical results on time optimal software ... Keywords: VLIW, compiler optimization, instruction-level parallelism, software pipelining

Han-Saem Yun; Jihong Kim; Soo-Mook Moon

2003-10-01T23:59:59.000Z

14

Adaptive Real-Time Methodology for Optimizing Energy-Efficient...  

NLE Websites -- All DOE Office Websites (Extended Search)

Email Adaptive Real-Time Methodology for Optimizing Energy-Efficient Computing Dynamic voltage and frequency scaling (DVFS) is an effective way to reduce energy and power...

15

Real-Time Optimization Strategies for Building Systems  

E-Print Network (OSTI)

Jul 2, 2011 ... Abstract: We propose real-time optimization strategies for energy ... reductions of energy intensity compared with traditional strategies.

16

Efficient optimal design of uncertain discrete time dynamical systems  

Science Conference Proceedings (OSTI)

In this paper we consider the problem of optimal design of an uncertain discrete time nonlinear dynamical system. The problem is formulated using an a-posterori design criterion, which can account for uncertainties generated by the dynamics of the system ... Keywords: Discrete time dynamical systems, Optimal design, Randomized algorithms, Uncertain parameters

Chenxi Lin; Thordur Runolfsson

2012-10-01T23:59:59.000Z

17

Optimal resource allocation for time-reservation systems  

Science Conference Proceedings (OSTI)

This paper studies the optimal resource allocation in time-reservation systems. Customers arrive at a service facility and receive service in two steps; in the first step information is gathered from the customer, which is then sent to a pool of computing ... Keywords: Constrained Markov decision problems, Monotonicity, Optimal resource allocation, Queueing theory, Time-reservation systems

Ran Yang; Sandjai Bhulai; Rob van der Mei; Frank Seinstra

2011-05-01T23:59:59.000Z

18

Optimization of time-based rates in forward energy markets  

E-Print Network (OSTI)

This paper presents a new two-step design approach of Time-Based Rate (TBR) programs for markets with a high penetration of variable energy sources such as wind power. First, an optimal market time horizon must be determined ...

Wang, J.

19

ESTIMATED SIL LEVELS AND RISK COMPARISONS FOR RELIEF VALVES AS A FUNCTION OF TIME-IN-SERVICE  

SciTech Connect

Risk-based inspection methods enable estimation of the probability of spring-operated relief valves failing on demand at the United States Department of Energy's Savannah River Site (SRS) in Aiken, South Carolina. The paper illustrates an approach based on application of the Frechet and Weibull distributions to SRS and Center for Chemical Process Safety (CCPS) Process Equipment Reliability Database (PERD) proof test results. The methodology enables the estimation of ANSI/ISA-84.00.01 Safety Integrity Levels (SILs) as well as the potential change in SIL level due to modification of the maintenance schedule. Current SRS practices are reviewed and recommendations are made for extending inspection intervals. The paper compares risk-based inspection with specific SILs as maintenance intervals are adjusted. Groups of valves are identified in which maintenance times can be extended as well as different groups in which an increased safety margin may be needed.

Harris, S.

2012-03-26T23:59:59.000Z

20

Underwater vehicles: a surprising non time-optimal path This paper deals with the time-optimal problem for  

E-Print Network (OSTI)

Underwater vehicles: a surprising non time-optimal path M. Chyba Abstract This paper deals with the time-optimal problem for a class of underwater vehicles. We prove that if two configurations at rest or an underwater ve- hicle. This problem is a particularly challenging one and has been widely studied during

Sontag, Eduardo

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Optimal aggregation of linear time series models  

Science Conference Proceedings (OSTI)

Aggregation is a central and mainly unsolved problem in econometrics. When considering linear time series models, a widely used method is to replace the disaggregate model by an aggregative one in which the variables are grouped and replaced by sums ... Keywords: Aggregation, Industrial classification, Threshold accepting

J. Chipman; P. Winker

2005-04-01T23:59:59.000Z

22

Optimal Production Planning under Time-sensitive Electricity Prices for  

E-Print Network (OSTI)

Optimal Production Planning under Time-sensitive Electricity Prices for Continuous Power-dependent electricity pricing schemes. In this paper, we describe a deterministic MILP model that allows optimal week and hourly changing electricity prices, we solve an industrial case study on air separation plants

Grossmann, Ignacio E.

23

Run-time optimization of adaptive irregular applications  

E-Print Network (OSTI)

Compared to traditional compile-time optimization, run-time optimization could o?er signi?cant performance improvements when parallelizing and optimizing adaptive irregular applications, because it performs program analysis and adaptive optimizations during program execution. Run-time techniques can succeed where static techniques fail because they exploit the characteristics of input data, programs' dynamic behaviors, and the underneath execution environment. When optimizing adaptive irregular applications for parallel execution, a common observation is that the effectiveness of the optimizing transformations depends on programs' input data and their dynamic phases. This dissertation presents a set of run-time optimization techniques that match the characteristics of programs' dynamic memory access patterns and the appropriate optimization (parallelization) transformations. First, we present a general adaptive algorithm selection framework to automatically and adaptively select at run-time the best performing, functionally equivalent algorithm for each of its execution instances. The selection process is based on off-line automatically generated prediction models and characteristics (collected and analyzed dynamically) of the algorithm's input data, In this dissertation, we specialize this framework for automatic selection of reduction algorithms. In this research, we have identi?ed a small set of machine independent high-level characterization parameters and then we deployed an off-line, systematic experiment process to generate prediction models. These models, in turn, match the parameters to the best optimization transformations for a given machine. The technique has been evaluated thoroughly in terms of applications, platforms, and programs' dynamic behaviors. Speci?cally, for the reduction algorithm selection, the selected performance is within 2% of optimal performance and on average is 60% better than "Replicated Buffer," the default parallel reduction algorithm speci?ed by OpenMP standard. To reduce the overhead of speculative run-time parallelization, we have developed an adaptive run-time parallelization technique that dynamically chooses effcient shadow structures to record a program's dynamic memory access patterns for parallelization. This technique complements the original speculative run-time parallelization technique, the LRPD test, in parallelizing loops with sparse memory accesses. The techniques presented in this dissertation have been implemented in an optimizing research compiler and can be viewed as effective building blocks for comprehensive run-time optimization systems, e.g., feedback-directed optimization systems and dynamic compilation systems.

Yu, Hao

2004-08-01T23:59:59.000Z

24

Time-optimal trajectories for cooperative multi-manipulator systems  

Science Conference Proceedings (OSTI)

We present two schemes for planning the time-optimal trajectory for cooperative multi-manipulator system (CMMS) carrying a common object. We assume that the desired path is given and parameterizable by an arclength variable. Both approaches take into ...

S. B. Moon; S. Ahmad

1997-04-01T23:59:59.000Z

25

Plug valve  

SciTech Connect

This patent describes an improved plug valve wherein a novel shape for the valve plug and valve chamber provide mating surfaces for improved wear characteristics. The novel shape of the valve plug is a frustum of body of revolution of a curved known as a tractrix, a solid shape otherwise known as a peudosphere.

Wordin, J.J.

1989-11-07T23:59:59.000Z

26

Plug valve  

DOE Patents (OSTI)

An improved plug valve wherein a novel shape for the valve plug and valve chamber provide mating surfaces for improved wear characteristics. The novel shape of the valve plug is a frustum of a body of revolution of a curved known as a tractrix, a solid shape otherwise known as a peudosphere.

Wordin, John J. (Shelley, ID)

1989-01-01T23:59:59.000Z

27

Modeling and optimizing passive valve designs for the implantable Gold Micro-Shunt used in glaucoma treatment  

Science Conference Proceedings (OSTI)

Glaucoma is an age-related eye disease that causes ocular nerve damage, typically characterized by elevated intraocular pressure (IOP). Studies have shown that IOP can vary significantly on the order of days or even hours. Failure to control IOP spikes ... Keywords: Check-valve, Drainage device, Finite element analysis, Glaucoma, Intraocular pressure, MEMS

Judy L. Lin; Jason M. Clevenger

2009-06-01T23:59:59.000Z

28

A stochastic control model for optimal timing of climate policies  

Science Conference Proceedings (OSTI)

A stochastic control model is proposed as a paradigm for the design of optimal timing of greenhouse gas (GHG) emission abatement. The resolution of uncertainty concerning climate sensitivity and the technological breakthrough providing access to a carbon-free ... Keywords: Climate policies, Environmental hedging strategies, Piecewise deterministic Markov process, Stochastic control

O. Bahn; A. Haurie; R. Malhamé

2008-06-01T23:59:59.000Z

29

Real-Time Optimization Strategies for Building Systems  

E-Print Network (OSTI)

Our analysis indicates that it is possible to obtain energy savings of more than ... This information can be used to compute economic-optimal set-point ... This ability is key in reducing the exposure of buildings to real-time market volatility and.

30

Real-time nonlinear optimization as a generalized equation.  

SciTech Connect

We establish results for the problem of tracking a time-dependent manifold arising in real-time optimization by casting this as a parametric generalized equation. We demonstrate that if points along a solution manifold are consistently strongly regular, it is possible to track the manifold approximately by solving a single linear complementarity problem (LCP) at each time step. We derive sufficient conditions guaranteeing that the tracking error remains bounded to second order with the size of the time step even if the LCP is solved only approximately. We use these results to derive a fast, augmented Lagrangian tracking algorithm and demonstrate the developments through a numerical case study.

Zavala, V. M.; Anitescu, M. (Mathematics and Computer Science)

2010-11-11T23:59:59.000Z

31

Optimal Real-time Dispatch for Integrated Energy Systems  

DOE Green Energy (OSTI)

This report describes the development and application of a dispatch optimization algorithm for integrated energy systems (IES) comprised of on-site cogeneration of heat and electricity, energy storage devices, and demand response opportunities. This work is intended to aid commercial and industrial sites in making use of modern computing power and optimization algorithms to make informed, near-optimal decisions under significant uncertainty and complex objective functions. The optimization algorithm uses a finite set of randomly generated future scenarios to approximate the true, stochastic future; constraints are included that prevent solutions to this approximate problem from deviating from solutions to the actual problem. The algorithm is then expressed as a mixed integer linear program, to which a powerful commercial solver is applied. A case study of United States Postal Service Processing and Distribution Centers (P&DC) in four cities and under three different electricity tariff structures is conducted to (1) determine the added value of optimal control to a cogeneration system over current, heuristic control strategies; (2) determine the value of limited electric load curtailment opportunities, with and without cogeneration; and (3) determine the trade-off between least-cost and least-carbon operations of a cogeneration system. Key results for the P&DC sites studied include (1) in locations where the average electricity and natural gas prices suggest a marginally profitable cogeneration system, optimal control can add up to 67% to the value of the cogeneration system; optimal control adds less value in locations where cogeneration is more clearly profitable; (2) optimal control under real-time pricing is (a) more complicated than under typical time-of-use tariffs and (b) at times necessary to make cogeneration economic at all; (3) limited electric load curtailment opportunities can be more valuable as a compliment to the cogeneration system than alone; and (4) most of the trade-off between least-cost and least-carbon IES is determined during the system design stage; for the IES system considered, there is little difference between least-cost control and least-carbon control.

Firestone, Ryan Michael

2007-05-31T23:59:59.000Z

32

Fast valve  

DOE Patents (OSTI)

A fast valve is disclosed that can close on the order of 7 milliseconds. It is closed by the force of a compressed air spring with the moving parts of the valve designed to be of very light weight and the valve gate being of wedge shaped with O-ring sealed faces to provide sealing contact without metal to metal contact. The combination of the O-ring seal and an air cushion create a soft final movement of the valve closure to prevent the fast air acting valve from having a harsh closing. 4 figs.

Van Dyke, W.J.

1992-04-07T23:59:59.000Z

33

Fast valve  

DOE Patents (OSTI)

A fast valve is disclosed that can close on the order of 7 milliseconds. It is closed by the force of a compressed air spring with the moving parts of the valve designed to be of very light weight and the valve gate being of wedge shaped with O-ring sealed faces to provide sealing contact without metal to metal contact. The combination of the O-ring seal and an air cushion create a soft final movement of the valve closure to prevent the fast air acting valve from having a harsh closing.

Van Dyke, William J. (Grafton, VA)

1992-01-01T23:59:59.000Z

34

Heart Valve Lesson Plan Biomedical Engineering  

E-Print Network (OSTI)

Heart Valve Lesson Plan Biomedical Engineering Objective · Introduce students to biomedical Learning Outcomes · Students will understand the role and function of heart valves. · Students will learn does a heart valve work? · Why do we need to replace heart valves? Time Required (Itemized) · Lecture

Provancher, William

35

Repsol Cartagena Utilities Real Time Optimization -- A Success Story  

E-Print Network (OSTI)

"In 1998 Honeywell Hi-Spec Solutions successfully implemented a Utilities Optimization system at Repsol's Cartagena Spain Refinery Complex. The Utilities Optimization System is implemented using Honeywell's Hi-Spec Solutions ProfitMax R100 system for Real Time Optimization (RTO) which runs on an NT-based workstation. ProfitMax uses the NOVA modeling system from DOT Products Inc. for non-linear modeling and optimization. Data is supplied through Uniformance PHD, Honeywell Hi-Spec Solutions' real time database. The cogeneration system is controlled using Honeywell's IDC 3000 system. The Utility System at Repsol Cartagena refinery is a cogeneration system that supplies both electricity and steam to the site. The surplus electricity is exported to the National grid. The system consists of the following: • Gas Turbine and Heat Recovery Steam Generator • Four fired boilers • Four steam headers at various pressures • Three Back-Pressure/Condensing steam turbo-generators • Plant condensate system • Fuel gas collection and distribution system • Process steam producers and consumers • Numerous dual drivers (steam/electric) for various plant loads "

Piccolo, M.; Shyr, S.

1999-05-01T23:59:59.000Z

36

Optimal Real-time Dispatch for Integrated Energy Systems  

E-Print Network (OSTI)

absorption chiller and space-heating. optimal dispatch – The full optimizationabsorption chiller and space-heating. optimal dispatch – The full optimization

Firestone, Ryan Michael

2007-01-01T23:59:59.000Z

37

An SQP-type solution method for constrained discrete-time optimal control problems  

Science Conference Proceedings (OSTI)

Keywords: constrained optimal control, discrete-time systems, hydroelectric power-station systems, structured nonlinear programming

E. Arnold; H. Puta

1994-03-01T23:59:59.000Z

38

Technology Competition and Optimal investment Timing: A Real Options Perspective  

E-Print Network (OSTI)

Companies often choose to defer irreversible investments to maintain valuable managerial flexibility in an uncertain world. For some technology-intensive projects, technology uncertainty plays a dominant role in affecting investment timing. This article analyzes the investment timing strategy for a firm that is deciding about whether to adopt one or the other of two incompatible and competing technologies. We develop a continuous-time stochastic model that aids in the determination of optimal timing for managerial adoption within the framework of real options theory. The model captures the elements of the decisionmaking process in such a way so as to provide managerial guidance in light of expectations associated with future technology competition. The results of this study suggest that a technology adopter should defer its investment until one technology’s probability to win out in the marketplace and achieve critical mass reaches a critical threshold. The optimal timing strategy for adoption that we propose can also be used in markets that are subject to positive network feedback. Although network effects usually tend to make the market equilibrium less stable and shorten the process of technology competition, we show why technology adopters may require more technology uncertainties to be

Robert J. Kauffman; Xiaotong Li

2005-01-01T23:59:59.000Z

39

Timing modeling and optimization under the transmission line model  

E-Print Network (OSTI)

Abstract—As the operating frequency increases to gigahertz and the rise time of a signal is less than or comparable to the time-of-flight delay of a wire, it is necessary to consider the transmission line behavior for delay computation. We present in this paper, an analytical formula for the delay computation under the transmission line model. Extensive simulations with SPICE show the high fidelity of the formula. Compared with previous works, our model leads to smaller average errors in delay estimation. Based on this formula, we show the property that the minimum delay for a transmission line with reflection occurs when the number of round trips is minimized (i.e., equals one). Besides, we show that the delay of a circuit path is a posynomial function in wire and buffer sizes, implying that a local optimum is equal to the global optimum. Thus, we can apply any efficient search algorithm such as the well-known gradient search procedure to compute the globally optimal solution. Experimental results show that simultaneous wire and buffer sizing is very effective for performance optimization under the transmission line model. Index Terms—Buffer sizing, delay model, inductance, interconnect, performance optimization, transmission line, wire sizing.

Tai-chen Chen; Song-ra Pan; Yao-wen Chang

2004-01-01T23:59:59.000Z

40

Optimal Real-time Dispatch for Integrated Energy Systems  

E-Print Network (OSTI)

the optimization of cogeneration dispatch in a deregulatedcomprised of on-site cogeneration of heat and electricity,of optimal control to a cogeneration system over current,

Firestone, Ryan Michael

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

An improved ant colony optimization and its application to vehicle routing problem with time windows  

Science Conference Proceedings (OSTI)

The ant colony optimization (ACO), inspired from the foraging behavior of ant species, is a swarm intelligence algorithm for solving hard combinatorial optimization problems. The algorithm, however, has the weaknesses of premature convergence and low ... Keywords: Ant colony optimization, Combinatorial optimization problems, Vehicle routing problem with time windows

Qiulei Ding; Xiangpei Hu; Lijun Sun; Yunzeng Wang

2012-12-01T23:59:59.000Z

42

Design trajectory stability analysis for the time-optimal system design algorithm  

Science Conference Proceedings (OSTI)

The operations number was evaluated for different design strategies to select the optimal or quasi-optimal strategy that has the minimal computer time. The general methodology for the system design was elaborated by means of the optimal control theory ... Keywords: Lyapunov function, control theory approach, design trajectory stability, optimal system design

Alexander Zemliak; Eduardo Rios

2005-03-01T23:59:59.000Z

43

Piezoelectric valve  

DOE Patents (OSTI)

A motorized valve has a housing having an inlet and an outlet to be connected to a pipeline, a saddle connected with the housing, a turn plug having a rod, the turn plug cooperating with the saddle, and a drive for turning the valve body and formed as a piezoelectric drive, the piezoelectric drive including a piezoelectric generator of radially directed standing acoustic waves, which is connected with the housing and is connectable with a pulse current source, and a rotor operatively connected with the piezoelectric generator and kinematically connected with the rod of the turn plug so as to turn the turn plug when the rotor is actuated by the piezoelectric generator.

Petrenko, Serhiy Fedorovich

2013-01-15T23:59:59.000Z

44

Plasma valve  

DOE Patents (OSTI)

A plasma valve includes a confinement channel and primary anode and cathode disposed therein. An ignition cathode is disposed adjacent the primary cathode. Power supplies are joined to the cathodes and anode for rapidly igniting and maintaining a plasma in the channel for preventing leakage of atmospheric pressure through the channel.

Hershcovitch, Ady (Mount Sinai, NY); Sharma, Sushil (Hinsdale, IL); Noonan, John (Naperville, IL); Rotela, Elbio (Clarendon Hills, IL); Khounsary, Ali (Hinsdale, IL)

2003-01-01T23:59:59.000Z

45

Time optimization and state-dependent constraints in the quantum optimal control of molecular orientation  

E-Print Network (OSTI)

We apply two recent generalizations of monotonically convergent optimization algorithms to the control of molecular orientation by laser fields. We show how to minimize the control duration by a step-wise optimization and maximize the field-free molecular orientation using state-dependent constraints. We discuss the physical relevance of the different results.

M. Ndong; C. Koch; D. Sugny

2013-08-03T23:59:59.000Z

46

Optimal experiment design for time-lapse traveltime tomography  

SciTech Connect

Geophysical monitoring techniques offer the only noninvasive approach capable of assessing both the spatial and temporal dynamics of subsurface fluid processes. Increasingly, permanent sensor arrays in boreholes and on the ocean floor are being deployed to improve the repeatability and increase the temporal sampling of monitoring surveys. Because permanent arrays require a large up-front capital investment and are difficult (or impossible) to re-configure once installed, a premium is placed on selecting a geometry capable of imaging the desired target at minimum cost. We present a simple approach to optimizing downhole sensor configurations for monitoring experiments making use of differential seismic traveltimes. In our case, we use a design quality metric based on the accuracy of tomographic reconstructions for a suite of imaging targets. By not requiring an explicit singular value decomposition of the forward operator, evaluation of this objective function scales to problems with a large number of unknowns. We also restrict the design problem by recasting the array geometry into a low dimensional form more suitable for optimization at a reasonable computational cost. We test two search algorithms on the design problem: the Nelder-Mead downhill simplex method and the Multilevel Coordinate Search algorithm. The algorithm is tested for four crosswell acquisition scenarios relevant to continuous seismic monitoring, a two parameter array optimization, several scenarios involving four parameter length/offset optimizations, and a comparison of optimal multi-source designs. In the last case, we also examine trade-offs between source sparsity and the quality of tomographic reconstructions. One general observation is that asymmetric array lengths improve localized image quality in crosswell experiments with a small number of sources and a large number of receivers. Preliminary results also suggest that high-quality differential images can be generated using only a small number of optimally positioned sources.

Ajo-Franklin, J.B.

2009-10-01T23:59:59.000Z

47

The time optimal control problem with control constraints of the rectangular type for a class of ODEs  

E-Print Network (OSTI)

This paper studies a time optimal control problem with control constraints of the rectangular type for the linear multi-input time-varying ordinary di?erential equations. The aims of this study are to establish certain necessary and sufficient conditions for the optimal time and time optimal control, and to build up an al- gorithm for the optimal time and time optimal control.

Zhang, Can

2011-01-01T23:59:59.000Z

48

Artificial Heart Valve Design  

E-Print Network (OSTI)

Artificial Heart Valve Design Your Chance to be a Biomedical Engineer #12;Circulatory System Video #12;What is a Heart Valve? · Heart Valve Video #12;#12;What Does a Heart Valve Do? · Maintain the one direction flow of blood through the heart · Heart valves allow blood to flow through in a forward direction

Provancher, William

49

Optimal Real-time Dispatch for Integrated Energy Systems  

E-Print Network (OSTI)

In these figures the real-time price is plotted on the rightto 6:00 PM 7.2.4.3 Real-time Prices City specific hourlyIn these figures the real-time price is plotted on the right

Firestone, Ryan Michael

2007-01-01T23:59:59.000Z

50

Optimal Real-time Dispatch for Integrated Energy Systems  

E-Print Network (OSTI)

is restricted to a maximum demand level determined by thedemand charge ($/kW maximum demand) site demand generatorparameters: load demand, maximum time until rescheduled

Firestone, Ryan Michael

2007-01-01T23:59:59.000Z

51

Optimization Online - The Delivery Man Problem with Time Windows  

E-Print Network (OSTI)

Sep 1, 2009 ... Abstract: In this paper, a variant of the Traveling Salesman Problem with Time Windows is considered, which consists in minimizing the sum of ...

52

Early cancellation: an active NIC optimization for time-warp  

Science Conference Proceedings (OSTI)

Parallel Discrete Event Simulation (PDES) on a cluster of workstations is a fine grained application where the communication performance can dictate the effiency of the simulation. The high performance Local/System Area Networks used in high-end clusters ... Keywords: clusters, global virtual time, programmable NIC, time warp event simulation

Ranjit Noronha; Nael B. Abu-Ghazaleh

2002-05-01T23:59:59.000Z

53

Nuclear radiation actuated valve  

DOE Patents (OSTI)

A nuclear radiation actuated valve for a nuclear reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

Christiansen, David W. (Kennewick, WA); Schively, Dixon P. (Richland, WA)

1985-01-01T23:59:59.000Z

54

Optimal Real-time Dispatch for Integrated Energy Systems  

E-Print Network (OSTI)

The cost of energy consumption at peak times is higher thantime constraints, variable maintenance costs, fixed-batch energytime-step of the timespan • E(cost()) is the expected energy

Firestone, Ryan Michael

2007-01-01T23:59:59.000Z

55

Optimal observation time window for forecasting the next earthquake  

Science Conference Proceedings (OSTI)

We report that the accuracy of predicting the occurrence time of the next earthquake is significantly enhanced by observing the latest rate of earthquake occurrences. The observation period that minimizes the temporal uncertainty of the next occurrence is on the order of 10 hours. This result is independent of the threshold magnitude and is consistent across different geographic areas. This time scale is much shorter than the months or years that have previously been considered characteristic of seismic activities.

Omi, Takahiro; Shinomoto, Shigeru [Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Kanter, Ido [Minerva Center and Department of Physics, Bar-Ilan University, Ramat-Gan, 52900 (Israel)

2011-02-15T23:59:59.000Z

56

Simulation of a novel electromechanical engine valve drive to quantify performance gains in fuel consumption  

E-Print Network (OSTI)

This thesis describes the modeling and simulation of a novel electromechanical valve drive known as the MIT EMV. This valve drive allows an engine to achieve variable valve timing which has been shown to produce improvements ...

Miller, Justin (Justin Lee)

2011-01-01T23:59:59.000Z

57

Optimal Updating of Forecasts for the Timing of Future Events  

Science Conference Proceedings (OSTI)

A major problem in forecasting is estimating the time of some future event. traditionally, forecasts are designed to minimize an error cost function that is evaluated once, possibly when the event occurs and forecast accuracy can be determined. However, ... Keywords: Air Transportation, Dynamic Programming Applications, Forecasting

Juhwen Hwang; Medini R. Singh; W. J. Hurley; Robert A. Shumsky

1998-03-01T23:59:59.000Z

58

Dynamic programming for constrained optimal control of discrete-time linear hybrid systems  

Science Conference Proceedings (OSTI)

In this paper we study the solution to optimal control problems for constrained discrete-time linear hybrid systems based on quadratic or linear performance criteria. The aim of the paper is twofold. First, we give basic theoretical results on the structure ... Keywords: Dynamic programming, Hybrid systems, Multiparametric programming, Optimal control, Piecewise affine systems

Francesco Borrelli; Mato Baoti?; Alberto Bemporad; Manfred Morari

2005-10-01T23:59:59.000Z

59

The benefits and costs of DyC's run-time optimizations  

Science Conference Proceedings (OSTI)

DyC selectively dynamically compiles programs during their execution, utilizing the run-time-computed values of variables and data structures to apply optimizations that are based on partial evaluation. The dynamic optimizations are preplanned at static ... Keywords: dynamic compilation, specialization

Brian Grant; Markus Mock; Matthai Philipose; Craig Chambers; Susan J. Eggers

2000-09-01T23:59:59.000Z

60

An Exact Solution Procedure for Determining the Optimal Dispatching Times for Complex Rail Networks  

E-Print Network (OSTI)

in an optimal way is an important research issue in rail freight transportation. In this paper, we propose a new train service in order to compete with alternative modes of freight transportation. To achieve this1 An Exact Solution Procedure for Determining the Optimal Dispatching Times for Complex Rail

Dessouky, Maged

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Optease Vena Cava Filter Optimal Indwelling Time and Retrievability  

SciTech Connect

The purpose of this study was to assess the indwelling time and retrievability of the Optease IVC filter. Between 2002 and 2009, a total of 811 Optease filters were inserted: 382 for prophylaxis in multitrauma patients and 429 for patients with venous thromboembolic (VTE) disease. In 139 patients [97 men and 42 women; mean age, 36 (range, 17-82) years], filter retrieval was attempted. They were divided into two groups to compare change in retrieval policy during the years: group A, 60 patients with filter retrievals performed before December 31 2006; and group B, 79 patients with filter retrievals from January 2007 to October 2009. A total of 128 filters were successfully removed (57 in group A, and 71 in group B). The mean filter indwelling time in the study group was 25 (range, 3-122) days. In group A the mean indwelling time was 18 (range, 7-55) days and in group B 31 days (range, 8-122). There were 11 retrieval failures: 4 for inability to engage the filter hook and 7 for inability to sheathe the filter due to intimal overgrowth. The mean indwelling time of group A retrieval failures was 16 (range, 15-18) days and in group B 54 (range, 17-122) days. Mean fluoroscopy time for successful retrieval was 3.5 (range, 1-16.6) min and for retrieval failures 25.2 (range, 7.2-62) min. Attempts to retrieve the Optease filter can be performed up to 60 days, but more failures will be encountered with this approach.

Rimon, Uri, E-mail: rimonu@sheba.health.gov.il; Bensaid, Paul, E-mail: paulbensaid@hotmail.com; Golan, Gil, E-mail: gilgolan201@gmail.com; Garniek, Alexander, E-mail: garniek@gmail.com; Khaitovich, Boris, E-mail: borislena@012.net.il [Chaim Sheba Medical Center (Affiliated to the Sackler School of Medicine, Tel-Aviv University, Tel-Aviv), Department of Diagnostic Imaging (Israel); Dotan, Zohar, E-mail: Zohar.Dotan@sheba.health.gov.il [Chaim Sheba Medical Center (Affiliated to the Sackler School of Medicine, Tel-Aviv University, Tel-Aviv), Department of Urology (Israel); Konen, Eli, E-mail: Eli.Konen@sheba.health.gov.il [Chaim Sheba Medical Center (Affiliated to the Sackler School of Medicine, Tel-Aviv University, Tel-Aviv), Department of Diagnostic Imaging (Israel)

2011-06-15T23:59:59.000Z

62

Improved plug valve  

DOE Patents (OSTI)

An improved plug valve wherein a novel shape for the valve plug and valve chamber provide mating surfaces for improved wear characteristics is described. The novel shape of the valve plug is a frustum of a body of revolution of a curve known as a tractrix, a solid shape otherwise known as a pseudosphere.

Wordin, J.J.

1986-05-09T23:59:59.000Z

63

Rotary pneumatic valve  

DOE Patents (OSTI)

A rotary pneumatic valve which is thrust balanced and the pneumatic pressure developed produces only radial loads on the valve cylinder producing negligible resistance and thus minimal torque on the bearings of the valve. The valve is multiplexed such that at least two complete switching cycles occur for each revolution of the cylinder spindle. 4 figs.

Hardee, H.C.

1989-08-02T23:59:59.000Z

64

Optimal Fingerprints for the Detection of Time-dependent Climate Change  

Science Conference Proceedings (OSTI)

An optimal linear filter (fingerprint) is derived for the detection of a given time-dependent, multivariate climate change signal in the presence of natural climate variability noise. Application of the fingerprint to the observed (or model ...

K. Hasselmann

1993-10-01T23:59:59.000Z

65

Real-Time Loop Scheduling with Energy Optimization Via DVS and ...  

Science Conference Proceedings (OSTI)

Real-Time Loop Scheduling with Energy. Optimization Via DVS and ABB for Multi -core. Embedded System. Guochen Hua1, Meng Wang1, Zili Shao1, Hui Liu2, ...

66

Vacuum breaker valve assembly  

DOE Patents (OSTI)

Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening.

Thompson, Jeffrey L. (San Jose, CA); Upton, Hubert Allen (Morgan Hill, CA)

1999-04-27T23:59:59.000Z

67

Vacuum breaker valve assembly  

Science Conference Proceedings (OSTI)

Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening. 1 fig.

Thompson, J.L.; Upton, H.A.

1999-04-27T23:59:59.000Z

68

A modified parallel optimization system for updating large-size time-evolving flow matrix  

Science Conference Proceedings (OSTI)

Flow matrices are widely used in many disciplines, but few methods can estimate them. This paper presents a knowledge-based system as capable of estimating and updating large-size time-evolving flow matrix. The system in this paper consists of two major ... Keywords: Data fusion, Parallel optimization, Time-evolving flow matrix

Ting Yu; Julien Ugon; Wei Yu

2012-07-01T23:59:59.000Z

69

Acoustic classification of the state of artificial heart valves  

Science Conference Proceedings (OSTI)

Transthoracic acoustic signals from BSCC (Björk–Shiley convexo–concave) mechanical heart valves implanted in human patients were processed to determine if the valves had separated outflow struts. For normal valves with intact outflow struts it is demonstrated that a time?windowed spectral analysis reveals the resonant frequency of the vibrating strut. The strut

Terry D. Plemons; Michael Hovenga

1995-01-01T23:59:59.000Z

70

PARLO: PArallel Run-Time Layout Optimization for Scientific Data Explorations with Heterogeneous Access Pattern  

SciTech Connect

Download Citation Email Print Request Permissions Save to Project The size and scope of cutting-edge scientific simulations are growing much faster than the I/O and storage capabilities of their run-time environments. The growing gap is exacerbated by exploratory, data-intensive analytics, such as querying simulation data with multivariate, spatio-temporal constraints, which induces heterogeneous access patterns that stress the performance of the underlying storage system. Previous work addresses data layout and indexing techniques to improve query performance for a single access pattern, which is not sufficient for complex analytics jobs. We present PARLO a parallel run-time layout optimization framework, to achieve multi-level data layout optimization for scientific applications at run-time before data is written to storage. The layout schemes optimize for heterogeneous access patterns with user-specified priorities. PARLO is integrated with ADIOS, a high-performance parallel I/O middleware for large-scale HPC applications, to achieve user-transparent, light-weight layout optimization for scientific datasets. It offers simple XML-based configuration for users to achieve flexible layout optimization without the need to modify or recompile application codes. Experiments show that PARLO improves performance by 2 to 26 times for queries with heterogeneous access patterns compared to state-of-the-art scientific database management systems. Compared to traditional post-processing approaches, its underlying run-time layout optimization achieves a 56% savings in processing time and a reduction in storage overhead of up to 50%. PARLO also exhibits a low run-time resource requirement, while also limiting the performance impact on running applications to a reasonable level.

Gong, Zhenhuan [North Carolina State University, Raleigh; Boyuka, David [North Carolina State University, Raleigh; Zou, X [North Carolina State University, Raleigh; Liu, Gary [ORNL; Podhorszki, Norbert [ORNL; Klasky, Scott A [ORNL; Ma, Xiaosong [North Carolina State University, Raleigh; Samatova, Nagiza F [ORNL

2013-01-01T23:59:59.000Z

71

Neural-optimal control algorithm for real-time regulation of in-line storage in combined sewer systems  

Science Conference Proceedings (OSTI)

Attempts at implementing real-time control systems as a cost-effective means of minimizing the pollution impacts of untreated combined sewer overflows have largely been unsustained due to the complexity of the real-time control problem. Optimal real-time ... Keywords: Artificial intelligence, Combined sewers, Hydraulic sewer models, Neural networks, Optimal control, Real-time control, Urban stormwater management

Suseno Darsono; John W. Labadie

2007-09-01T23:59:59.000Z

72

Brief paper: Discrete-time drift counteraction stochastic optimal control: Theory and application-motivated examples  

Science Conference Proceedings (OSTI)

We develop stochastic optimal control results for nonlinear discrete-time systems driven by disturbances modeled by a Markov chain. A characterization and a computational procedure for a control law which maximizes a cost functional, related to expected ... Keywords: Automotive applications, Constrained systems, Dynamic programming, Hybrid electric vehicles, Stochastic control

I. V. Kolmanovsky; L. Lezhnev; T. L. Maizenberg

2008-01-01T23:59:59.000Z

73

Loop transformations in the ahead-of-time optimization of java bytecode  

Science Conference Proceedings (OSTI)

Loop optimizations such as loop unrolling, unfolding and invariant code motion have long been used in a wide variety of compilers to improve the running time of applications. In this paper we present a series of experimental results detailing the effect ...

Simon Hammond; David Lacey

2006-03-01T23:59:59.000Z

74

A time management optimization framework for large-scale distributed hardware-in-the-loop simulation  

Science Conference Proceedings (OSTI)

Large-scale distributed HIL(Hardware-In-The-Loop) simulation is an important and indispensable method for testing and verifying complex engineering systems. An important necessary condition for realizing HIL simulation is that the speedup ratio of full-speed ... Keywords: hardware-in-the-loop simulation, large-scale distributed simulation, optimization framework, speedup ratio of simulation, time management

Wei Dong

2013-05-01T23:59:59.000Z

75

Application of Particle Swarm Optimization technique for achieving desired milled surface roughness in minimum machining time  

Science Conference Proceedings (OSTI)

Face milling is a widely used machining operation to produce various components. The finished component depends not only on the dimensional accuracy but also on the surface finish. The present method of selection of machining parameters by trial and ... Keywords: Face milling, Machining parameters, Machining time, Particle Swarm Optimization, Surface roughness

S. Bharathi Raja; N. Baskar

2012-04-01T23:59:59.000Z

76

Optimal Real-time Pricing Algorithm Based on Utility Maximization for Smart Grid  

E-Print Network (OSTI)

Optimal Real-time Pricing Algorithm Based on Utility Maximization for Smart Grid Pedram Samadi algorithm for the future smart grid. We focus on the interactions between the smart meters and the energy-mail:{psamadi, hamed, rschober, vincentw, jurij}@ece.ubc.ca Abstract--In this paper, we consider a smart power infras

Wong, Vincent

77

Engine Valve Actuation For Combustion Enhancement  

DOE Patents (OSTI)

A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-stroke combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Reitz, Rolf Deneys (Madison, WI); Rutland, Christopher J. (Madison, WI); Jhavar, Rahul (Madison, WI)

2004-05-18T23:59:59.000Z

78

Engine valve actuation for combustion enhancement  

DOE Patents (OSTI)

A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-strokes combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Reitz, Rolf Deneys (Madison, WI); Rutland, Christopher J. (Madison, WI); Jhavar, Rahul (Madison, WI)

2008-03-04T23:59:59.000Z

79

Input Price Risk and Optimal Timing of Energy Investment: Choice between Fossil- and Biofuels  

E-Print Network (OSTI)

Ve consider energy investment, when a choice has to be made between fossil fuel and biomass fired production technologies. A dynamic model is presented to illustrate the effect of the different degrees of input price uncer- tainty on the choice of technolog2 and the timing of the investment. It is shown that when the choice of technology is irreversible, it may be optimal to postpone the investment even if it would otherwise be optimal to invest in one or both of the plant types. Ve provide a numerical example based on cost estimates of two different power plant types.

Pauli Murto; Gjermund Nese

2002-01-01T23:59:59.000Z

80

A study on the use of multiple surrogate models in valve design  

Science Conference Proceedings (OSTI)

Nowadays, the use of computational fluid dynamics (CFD) in the design of valves is very common. Despite the continuing growth of computing capability, the computational cost of complex three-dimensional CFD analysis of butterfly valve maintains high, ... Keywords: DOE, butterfly valve, error analysis, multiple surrogate models, optimization

Xue Guan Song; Jeong Ju Choi; Joon-Ho Lee; Young Chul Park

2011-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

By-pass valve  

Science Conference Proceedings (OSTI)

An improved by-pass valve (1) for use in an automobile exhaust system (Es) comprises an air inlet (7) connected to an air pump (Ap), first and second air outlets (15,23) respectively connected to first and second portions (P1,p2) of a catalytic converter (Cc) and a third outlet (33) through which air is dumped to atmosphere. Air is directed from the inlet to the first outlet when engine temperature is less than a predetermined value and from the inlet to the second outlet when engine temperature reaches the predetermined value. A first and normally closed valve (81) is intermediate the air inlet and the first and second outlets and a second and normally open valve (83) is intermediate the air inlet and the third outlet. The first valve is opened and the second valve closed when engine vacuum exceeds a predetermined level so air flows to either the first or second outlet. The second valve is reopened whenever the outlet to which air is directed is blocked so air is dumped to atmosphere. To accomplish this, the first valve is mounted on the first section (111) of a split shaft (109) and the second valve is mounted on a second shaft section (113). The sections are movable in unison to open the first valve, but the second section is movable relative to the first section when a blockage occurs to reopen the second valve.

Williamson, R.E.

1981-01-06T23:59:59.000Z

82

Symmetry breaking in optimal timing of traffic signals on an idealized two-way street  

E-Print Network (OSTI)

Simple physical models based on fluid mechanics have long been used to understand the flow of vehicular traffic on freeways; analytically tractable models of flow on an urban grid, however, have not been as extensively explored. In an ideal world, traffic signals would be timed such that consecutive lights turned green just as vehicles arrived, eliminating the need to stop at each block. Unfortunately, this "green wave" scenario is generally unworkable due to frustration imposed by competing demands of traffic moving in different directions. Until now this has typically been resolved by numerical simulation and optimization. Here, we develop a theory for the flow in an idealized system consisting of a long two-way road with periodic intersections. We show that optimal signal timing can be understood analytically and that there are counter-intuitive asymmetric solutions to this signal coordination problem. We further explore how these theoretical solutions degrade as traffic conditions vary and automotive dens...

Panaggio, Mark J; Hu, Peiguang; Abrams, Daniel M

2013-01-01T23:59:59.000Z

83

Solid handling valve  

DOE Patents (OSTI)

The present invention is directed to a solids handling valve for use in combination with lock hoppers utilized for conveying pulverized coal to a coal gasifier. The valve comprises a fluid-actuated flow control piston disposed within a housing and provided with a tapered primary seal having a recessed seat on the housing and a radially expandable fluid-actuated secondary seal. The valve seals are highly resistive to corrosion, erosion and abrasion by the solids, liquids, and gases associated with the gasification process so as to minimize valve failure.

Williams, William R. (Morgantown, WV)

1979-01-01T23:59:59.000Z

84

Compact gate valve  

DOE Patents (OSTI)

This invention relates to a double-disc gate valve which is compact, comparatively simple to construct, and capable of maintaining high closing pressures on the valve discs with low frictional forces. The valve casing includes axially aligned ports. Mounted in the casing is a sealed chamber which is pivotable transversely of the axis of the ports. The chamber contains the levers for moving the valve discs axially, and an actuator for the levers. When an external drive means pivots the chamber to a position where the discs are between the ports and axially aligned therewith, the actuator for the levers is energized to move the discs into sealing engagement with the ports.

Bobo, Gerald E. (Knoxville, TN)

1977-01-01T23:59:59.000Z

85

Tubing drain valve  

SciTech Connect

A method is described for operating a valve means. The valve means comprises a tubular piston movable within a tubular member suitable for use in a borehole pipe string to open and close a port through the wall of the tubular member. The method comprises: biassing the valve means in its closed position; pressurizing the interior of the piston to a predetermined pressure to overcome the biassing closed force and to actuate the valve means to its open position; biassing the valve means to its open position; and actuating the valve means to its closed position by engaging a first arm of a dog pivotally mounted on the piston with an engaging means insertable through the interior of the tubular piston; moving the piston relative to the tubular member; rotating the dog about its pivot to bring a second arm of the dog into contact with a detent in the tubular member; and applying sufficient force to the first arm to continue rotating the dog about the pivot, while engaging the detent with the second arm of the dog, in order to overcome the biassing open force to actuate the valve means to its closed position. A tubing drain valve suitable for use in a borehole pipe string, comprising: a sub suitable for incorporating within a borehole pipe string; and a port between the interior and the exterior of the sub; and valve means for opening and closing the port.

Soderberg, P.B.

1987-02-24T23:59:59.000Z

86

Time-optimal CNOT between indirectly coupled qubits in a linear Ising chain  

E-Print Network (OSTI)

We give analytical solutions for the time-optimal synthesis of entangling gates between indirectly coupled qubits 1 and 3 in a linear spin chain of three qubits subject to an Ising Hamiltonian interaction with equal coupling $J$ plus a local magnetic field acting on the intermediate qubit. The energy available is fixed, but we relax the standard assumption of instantaneous unitary operations acting on single qubits. The time required for performing an entangling gate which is equivalent, modulo local unitary operations, to the $\\mathrm{CNOT}(1, 3)$ between the indirectly coupled qubits 1 and 3 is $T=\\sqrt{3/2} J^{-1}$, i.e. faster than a previous estimate based on a similar Hamiltonian and the assumption of local unitaries with zero time cost. Furthermore, performing a simple Walsh-Hadamard rotation in the Hlibert space of qubit 3 shows that the time-optimal synthesis of the $\\mathrm{CNOT}^{\\pm}(1, 3)$ (which acts as the identity when the control qubit 1 is in the state $\\ket{0}$, while if the control qubit is in the state $\\ket{1}$ the target qubit 3 is flipped as $\\ket{\\pm}\\rightarrow \\ket{\\mp}$) also requires the same time $T$.

A. Carlini; A. Hosoya; T. Koike; Y. Okudaira

2010-09-29T23:59:59.000Z

87

Optimal Constant-Time Approximation Algorithms and (Unconditional) Inapproximability Results for Every Bounded-Degree CSP  

E-Print Network (OSTI)

Raghavendra (STOC 2008) gave an elegant and surprising result: if Khot's Unique Games Conjecture (STOC 2002) is true, then for every constraint satisfaction problem (CSP), the best approximation ratio is attained by a certain simple semidefinite programming and a rounding scheme for it. In this paper, we show that a similar result holds for constant-time approximation algorithms in the bounded-degree model. Specifically, we present the followings: (i) For every CSP, we construct an oracle that serves an access, in constant time, to a nearly optimal solution of a basic LP relaxation of the CSP. (ii) Using the oracle, we present a constant-time rounding scheme that achieves an approximation ratio coincident with the integrality gap of the basic LP. (iii) We give a generic conversion from integrality gaps of basic LPs to hardness results. All of those results are ``unconditional.'' Therefore, for every bounded-degree CSP, we give the best constant-time approximation algorithm among all.

Yoshida, Yuichi

2010-01-01T23:59:59.000Z

88

Light incoherence theory revisited by Heisenberg time-energy uncertainty challenges solar cell optimization  

E-Print Network (OSTI)

Optimization of the efficiency of solar cells is a major challenge for renewable energies. Using a rigorous theoretical approach, we show that the photocurrent generated in a solar cell depends strongly on the degree of coherence of the incident light. In accordance with Heisenberg uncertainty time-energy, incoherent light at photons of carrier energy lower than the active material bandgap can be absorbed whereas coherent light at the same carrier energy cannot. We identify cases where incoherence does enhance efficiency. This result has a dramatical impact on the way solar cells must be optimized regarding sunlight. As an illustration, surface-corrugated GaAs and c-Si thin-film solar cells are considered.

Herman, Aline; Deparis, Olivier

2013-01-01T23:59:59.000Z

89

Impacts of time-of-use rates on the optimal sizing and operation of cogeneration systems  

SciTech Connect

For customers with a cogeneration system (CGS), a mixed-integer programming and nonlinear programming model is used to examine effects of time-of-use (TOU) rates on the optimal operation of the constituent equipment as well as the optimal sizing. Three customers are selected for case studies: a hotel, a hospital, and an office building. Effects of an on-peak/off-peak energy charge ratio on purchased power share in the total electricity demand are saturated at the ratio of 5. As the energy charge ratio is raised, cheaper off-peak power substitutes for city gas and the operating cost decreases. The responses of the hotel and the hospital are similar. The simulation results included in this paper indicate that properly designed TOU rates can provide commercial customers an incentive to operate a CGS with an appropriate mix of the self-generation and commercial power.

Asano, H.; Sagai, S.; Imamura, E. (Central Research Inst. of Electric Power Industry, Tokyo (Japan)); Ito, K.; Yokoyama, R. (Osaka Prefectural Univ., Sakai (Japan))

1992-11-01T23:59:59.000Z

90

Corrosion of valve metals  

DOE Green Energy (OSTI)

A general survey related to the corrosion of valve metals or film-forming metals. The way these metals corrode with some general examples is described. Valve metals form relatively perfect oxide films with little breakdown or leakage when anodized. (FS)

Draley, J.E.

1976-01-01T23:59:59.000Z

91

Valve for abrasive material  

DOE Patents (OSTI)

A ball valve assembly for controlling the flow of abrasive particulates including an enlarged section at the bore inlet and an enlarged section at the bore outlet. A refractory ceramic annular deflector is positioned in each of the enlarged sections, substantially extending the useful life of the valve.

Gardner, Harold S. (Turtle Creek, PA)

1982-01-01T23:59:59.000Z

92

Time-optimal CNOT between indirectly coupled qubits in a linear Ising chain  

E-Print Network (OSTI)

We give analytical solutions for the time-optimal synthesis of entangling gates between indirectly coupled qubits 1 and 3 in a linear spin chain of three qubits subject to an Ising Hamiltonian interaction with equal coupling $J$ plus a local magnetic field acting on the intermediate qubit 2. The energy available is fixed, but we relax the standard assumption of instantaneous unitary operations acting on single qubits. The time required for performing an entangling gate which is equivalent, modulo local unitary operations, to the $\\mathrm{CNOT}(1, 3)$ between the indirectly coupled qubits 1 and 3 is $T=\\sqrt{3/2} J^{-1}$, i.e. faster than a previous estimate based on a similar Hamiltonian and the assumption of local unitaries with zero time cost. Furthermore, performing a simple Walsh-Hadamard rotation in the Hlibert space of qubit 3 shows that the time-optimal synthesis of the $\\mathrm{CNOT}^{\\pm}(1, 3)$ (which acts as the identity when the control qubit 1 is in the state $\\ket{0}$, while if the control qubit...

Carlini, A; Koike, T; Okudaira, Y

2010-01-01T23:59:59.000Z

93

Real-Time Combined Heat and Power Operational Strategy Using a Hierarchical Optimization Algorithm  

Science Conference Proceedings (OSTI)

Existing attempts to optimize the operation of Combined Heat and Power (CHP) systems for building applications have two major limitations: the electrical and thermal loads are obtained from historical weather profiles; and the CHP system models ignore transient responses by using constant equipment efficiencies. This paper considers the transient response of a building combined with a hierarchical CHP optimal control algorithm to obtain a real-time integrated system that uses the most recent weather and electric load information. This is accomplished by running concurrent simulations of two transient building models. The first transient building model uses current as well as forecast input information to obtain short term predictions of the thermal and electric building loads. The predictions are then used by an optimization algorithm, i.e., a hierarchical controller, that decides the amount of fuel and of electrical energy to be allocated at the current time step. In a simulation, the actual physical building is not available and, hence, to simulate a real-time environment, a second, building model with similar but not identical input loads are used to represent the actual building. A state-variable feedback loop is completed at the beginning of each time step by copying, i.e., measuring, the state variable from the actual building and restarting the predictive model using these ?measured? values as initial conditions. The simulation environment presented in this paper features nonlinear effects such as the dependence of the heat exchanger effectiveness on their operating conditions. The results indicate that the CHP engine operation dictated by the proposed hierarchical controller with uncertain weather conditions have the potential to yield significant savings when compared to conventional systems using current values of electricity and fuel prices.

Yun, Kyung Tae; Cho, Heejin; Luck, Rogelio; Mago, Pedro J.

2011-06-01T23:59:59.000Z

94

A rotary-airlock valve resists abrasive mixtures  

SciTech Connect

Hill and Griffith (H and G, Cincinnati, Ohio) is a leading supplier of custom-blended additives to founderies. Thousands of tons of clay and carbon blends such as bentonite, gilsonite and pulverized coal, pass through the company's rotary-airlock feeding system each month. H and G's original rotary valves had cylinders lined with chrome, and closed-end rotors with tips made from nickel-chromium alloys. These valves remained in service for a maximum of only three months each. During that time, the abrasive mixtures passing through the valves virtually eroded them, increasing tolerances and causing significant air leakage. The leaks caused the pneumatic line to plug up, reducing the velocity of the line below the minimum level needed to carry any material. To overcome the leakage, a second blower was added to the system. This unit supplied an additional 40 brake hp to the pneumatic-conveying line. With constant maintenance of the valve and the continuous operation of both blowers, H and G was able to extend the valve's life by nine months. After 20 years of trying valves with various configuration, H and G installed a Smoot Type 6 rotary-airlock valve in September of 1985. The new valve's internals were made from abrasion-resistant grades of NiHard and Stellite. This combination of alloys prolonged the active life of the valve by improving its abrasion resistance. During its first year, the Smoot valve did not break down, leak air or require use of the secondary blower. After its first year of service no wear was found on the valve's internal surfaces. Another mechanical analysis was performed in 1991, after five additional years of valve operation. The valve, which had now handled more than 250,000 tons of product, showed minimal wear. H and G's capital costs had been reduced from 25[cents]/ton to 3[cents]/ton by the new valve.

Not Available

1993-03-01T23:59:59.000Z

95

Value of Probabilistic Weather Forecasts: Assessment by Real-Time Optimization of Irrigation Scheduling  

SciTech Connect

This paper presents a modeling framework for real-time decision support for irrigation scheduling using the National Oceanic and Atmospheric Administration's (NOAA's) probabilistic rainfall forecasts. The forecasts and their probability distributions are incorporated into a simulation-optimization modeling framework. In this study, modeling irrigation is determined by a stochastic optimization program based on the simulated soil moisture and crop water-stress status and the forecasted rainfall for the next 1-7 days. The modeling framework is applied to irrigated corn in Mason County, Illinois. It is found that there is ample potential to improve current farmers practices by simply using the proposed simulation-optimization framework, which uses the present soil moisture and crop evapotranspiration information even without any forecasts. It is found that the values of the forecasts vary across dry, normal, and wet years. More significant economic gains are found in normal and wet years than in dry years under the various forecast horizons. To mitigate drought effect on crop yield through irrigation, medium- or long-term climate predictions likely play a more important role than short-term forecasts. NOAA's imperfect 1-week forecast is still valuable in terms of both profit gain and water saving. Compared with the no-rain forecast case, the short-term imperfect forecasts could lead to additional 2.4-8.5% gain in profit and 11.0-26.9% water saving. However, the performance of the imperfect forecast is only slightly better than the ensemble weather forecast based on historical data and slightly inferior to the perfect forecast. It seems that the 1-week forecast horizon is too limited to evaluate the role of the various forecast scenarios for irrigation scheduling, which is actually a seasonal decision issue. For irrigation scheduling, both the forecast quality and the length of forecast time horizon matter. Thus, longer forecasts might be necessary to evaluate the role of forecasts for irrigation scheduling in a more effective way.

Cai, Ximing; Hejazi, Mohamad I.; Wang, Dingbao

2011-09-29T23:59:59.000Z

96

Enabling run-time memory data transfer optimizations at the system level with automated extraction of embedded software metadata information  

Science Conference Proceedings (OSTI)

The information about the run-time behavior of software applications is crucial for enabling system level optimizations for embedded systems. This embedded Software Metadata information is especially important today, because several complex multi-threaded ...

Alexandros Bartzas; Miguel Peon-Quiros; Stylianos Mamagkakis; Francky Catthoor; Dimitrios Soudris; Jose M. Mendias

2008-01-01T23:59:59.000Z

97

ANALYSIS OF CHECK VALVE DISC MOTION DURING A FLOW TRANSIENT  

SciTech Connect

An analysis of the dynamics of a check valve disc under the influence of a flow transient is presented. The impact velocities of the disc and the pressure surge resulting from extinguishing a fluid velocity are predicted. This analysis develops the equations of motion of a simple swing disc check valve from Newton's Second Law. Modifications of the analysis necessary for application to other types of valves are described. The developed equations are progiammed for the Philco-2000 digital computer in FORTRAN as the SLAM Code. The Code input consists of the characteristics of the valve and the flow transient. The output of the code includes the dynamics of the valve disc as a function of time and the pressure surge induced by valve closure. (H.G.G.)

Fuls, G.M.

1962-12-01T23:59:59.000Z

98

Dissolution Actuated Valve Sampler  

Engineers at the Savannah River National Laboratory (SRNL) have invented a new device for retrieving liquid samples.  The dissolution actuated valve sampler was developed to obtain pristine samples while operating without the assistance of a mast or ...

99

Flow metering valve  

DOE Patents (OSTI)

An apparatus for metering fluids at high pressures of about 20,000 to 60,000 psi is disclosed. The apparatus includes first and second plates which are positioned adjacent each other to form a valve chamber. The plates are made of materials which have substantially equal elastic properties. One plate has a planar surface area, and the other a recessed surface area defined by periphery and central lips. When the two plates are positioned in adjacent contacting relationship, a valve chamber is formed between the planar surface area and the recessed surface area. Fluid is introduced into the chamber and exits therefrom when a deformation occurs at positions where they no longer form a valve seat. This permits the metering of fluids at high pressures and at slow variable rates. Fluid then exits from the chamber until an applied external force becomes large enough to bring the valve seats back into contact.

Blaedel, Kenneth L. (Dublin, CA)

1985-01-01T23:59:59.000Z

100

Flow metering valve  

DOE Patents (OSTI)

An apparatus for metering fluids at high pressures of about 20,000 to 60,000 psi is disclosed. The apparatus includes first and second plates which are positioned adjacent each other to form a valve chamber. The plates are made of materials which have substantially equal elastic properties. One plate has a planar surface area, and the other a recessed surface area defined by periphery and central lips. When the two plates are positioned in adjacent contacting relationship, a valve chamber is formed between the planar surface area and the recessed surface area. Fluid is introduced into the chamber and exits therefrom when a deformation occurs at positions where they no longer form a valve seat. This permits the metering of fluids at high pressures and at slow variable rates. Fluid then exits from the chamber until an applied external force becomes large enough to bring the valve seats back into contact.

Blaedel, K.L.

1983-11-03T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Valve for gas centrifuges  

DOE Patents (OSTI)

The invention is a pneumatically operated valve assembly for simultaneously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two of the lines so closed. The valve assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

Hahs, Charles A. (Oak Ridge, TN); Burbage, Charles H. (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

102

Low noise control valve  

SciTech Connect

Noise is one of the problems associated with the use of any type of control valve in systems involving the flow of fluids. The advent of OSHA standards has prompted control valve manufacturers to design valves with special trim to lower the sound pressure level to meet these standards. However, these levels are in some cases too high, particularly when a valve must be located in or near an area where people are working at tasks requiring a high degree of concentration. Such locations are found around and near research devices and in laboratory-office areas. This paper describes a type of fluid control device presently being used at PPL as a bypass control valve in deionized water systems and designed to reduce sound pressure levels considerably below OSHA standards. Details of the design and construction of this constant pressure drop variable flow control valve are contained in the text and are shown in photographs and drawings. Test data taken are included. (auth)

Christie, R.S.

1975-01-01T23:59:59.000Z

103

Fast closing valve  

DOE Patents (OSTI)

A valve is provided for protecting the high vacuum of a particle accelera in the event of air leakage, wherein the valve provides an axially symmetrical passage to avoid disturbance of the partical beam during normal operation, and yet enables very rapid and tight closure of the beam-carrying pipe in the event of air leakage. The valve includes a ball member (30) which can rotate between a first position wherein a bore (32) in the member is aligned with the beam pipe, and a second position out of line with the pipe. A seal member (38) is flexibly sealed to the pipe, and has a seal end which can move tightly against the ball member after the bore has rotated out of line with the pipe, to thereby assure that the seal member does not retard rapid rotation of the ball valve member. The ball valve member can be rapidly rotated by a conductive arm (40) fixed to it and which is rotated by the discharge of a capacitor bank through coils (44, 45) located adjacent to the arm.

Hanson, Clark L. (Livermore, CA)

1984-01-10T23:59:59.000Z

104

EVALUATION OF SPRING OPERATED RELIEF VALVE MAINTENANCE INTERVALS AND EXTENSION OF MAINTENANCE TIMES USING A WEIBULL ANALYSIS WITH MODIFIED BAYESIAN UPDATING  

Science Conference Proceedings (OSTI)

The Savannah River Site (SRS) spring operated pressure relief valve (SORV) maintenance intervals were evaluated using an approach provided by the American Petroleum Institute (API RP 581) for risk-based inspection technology (RBI). In addition, the impact of extending the inspection schedule was evaluated using Monte Carlo Simulation (MCS). The API RP 581 approach is characterized as a Weibull analysis with modified Bayesian updating provided by SRS SORV proof testing experience. Initial Weibull parameter estimates were updated as per SRS's historical proof test records contained in the Center for Chemical Process Safety (CCPS) Process Equipment Reliability Database (PERD). The API RP 581 methodology was used to estimate the SORV's probability of failing on demand (PFD), and the annual expected risk. The API RP 581 methodology indicates that the current SRS maintenance plan is conservative. Cost savings may be attained in certain mild service applications that present low PFD and overall risk. Current practices are reviewed and recommendations are made for extending inspection intervals. The paper gives an illustration of the inspection costs versus the associated risks by using API RP 581 Risk Based Inspection (RBI) Technology. A cost effective maintenance frequency balancing both financial risk and inspection cost is demonstrated.

Harris, S.; Gross, R.; Mitchell, E.

2011-01-18T23:59:59.000Z

105

REACTOR SYSTEM AND CONTROL VALVE  

DOE Patents (OSTI)

Valves have been developed for controlling the flow of gaseous fluid through a passage or conduit. The valves have particular application in the cooling systems of gas; cooled reactors. (R.J.S.)

Fortescue, P.; Rickard, C.; Rose, D.

1963-01-01T23:59:59.000Z

106

Hydrogen gas relief valve  

SciTech Connect

An improved battery stack design for an electrochemical system having at least one cell from which a gas is generated and an electrolyte in communication with the cell is described. The improved battery stack design features means for defining a substantially closed compartment for containing the battery cells and at least a portion of the electrolyte for the system, and means in association with the compartment means for selectively venting gas from the interior of the compartment means in response to the level of the electrolyte within the compartment means. The venting means includes a relief valve having a float member which is actuated in response to the level of the electrolyte within the compartment means. This float member is adapted to close the relief valve when the level of the electrolyte is above a predetermined level and open the relief valve when the level of electrolyte is below this predetermined level.

Whittlesey, Curtis C. (Birmingham, MI)

1985-01-01T23:59:59.000Z

107

Self-regulating valve  

DOE Patents (OSTI)

A variable, self-regulating valve having a hydraulic loss coefficient proportional to a positive exponential power of the flow rate. The device includes two objects in a flow channel and structure which assures that the distance between the two objects is an increasing function of the flow rate. The range of spacing between the objects is such that the hydraulic resistance of the valve is an increasing function of the distance between the two objects so that the desired hydraulic loss coefficient as a function of flow rate is obtained without variation in the flow area.

Humphreys, D.A.

1982-07-20T23:59:59.000Z

108

Improved bellows sealed plug valve  

DOE Patents (OSTI)

It is an object of the present invention to provide a bellows sealed 1/4 turn valve wherein means are provided for translating linear motion to rotational motion between the bellows seal and the valve body. This paper details the features of the valve. 6 figs.

Dukas, S.J. Jr.

1989-10-29T23:59:59.000Z

109

Valve stem and packing assembly  

DOE Patents (OSTI)

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele`s pivot. The Schiele`s pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele`s pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele`s pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

Wordin, J.J.

1990-12-31T23:59:59.000Z

110

Optimal Scheduling of Industrial Combined Heat and Power Plants under Time-sensitive Electricity Prices  

E-Print Network (OSTI)

Combined heat and power (CHP) plants are widely used in industrial applications. In the aftermath of the recession, many of the associated production processes are under-utilized, which challenges the competitiveness of chemical companies. However, under-utilization can be a chance for tighter interaction with the power grid, which is in transition to the so-called smart grid, if the CHP plant can dynamically react to time-sensitive electricity prices. In this paper, we describe a generalized mode model on a component basis that addresses the operational optimization of industrial CHP plants. The mode formulation tracks the state of each plant component in a detailed manner and can account for different operating modes, e.g. fuel-switching for boilers and supplementary firing for gas turbines, and transitional behavior. Transitional behavior such as warm and cold start-ups, shutdowns and pre-computed start-up trajectories is modeled with modes as well. The feasible region of operation for each component is described based on input-output relationships that are thermodynamically sound, such as the Willans line for steam turbines. Furthermore, we emphasize the use of mathematically efficient logic constraints that allow solving the large-scale models fast. We provide an industrial case study and study the impact of different scenarios for under-utilization. 1

Sumit Mitra; Ignacioe. Grossmann

2012-01-01T23:59:59.000Z

111

Real-time optimization of a cascaded reservoirs hydropower plant based on fuzzy logic  

Science Conference Proceedings (OSTI)

One of the important industrial areas that involve complex nonlinear dynamics, control problems, and difficult optimization tasks is that of cascaded reservoirs hydropower plants. For the purpose of minimizing the non-hydraulic power production expenses ... Keywords: cascaded reservoirs, fuzzy logic, hydropower, nonlinear control, optimization

M. Mahmoud; K. Dutton

2007-03-01T23:59:59.000Z

112

Valve for cryogenic service  

DOE Patents (OSTI)

This patent relates to a valve for use with a liquefied gas at cryogenic temperatures in which a pair of joined knife edges are bellows controlled to contact an indium alloy seat in an annular slot when flow is to be stopped. The sealing alloy may be renewed by heating in situ. (auth)

Worwetz, H.A.

1975-09-02T23:59:59.000Z

113

Valve for gas centrifuges  

DOE Patents (OSTI)

The invention is pneumatically operated valve assembly for simulatenously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two on the lines so closed. The value assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

Hahs, C.A.; Rurbage, C.H.

1982-03-17T23:59:59.000Z

114

Valve selection handbook. Third edition  

Science Conference Proceedings (OSTI)

This book covers the fundamentals of value construction and application, and analyzes the different hazards and requirements of all types of industrial fluid flow situations. This book expands the coverage of pressure relief valves and rupture discs. It includes a new section on damping valve chatter, which is a serious problem in installations such as atomic power plants where valve chatter could have catastrophic consequences to the safety of the plant. There is also new information on performance of spring-loaded pressure relief valves and a closer examination of valve selection with respect to rupture discs and explosion venting.

Zappe, R.W. (ICI Australia Operations Pty. Ltd. (AU))

1991-01-01T23:59:59.000Z

115

Dual valve well pump installation  

SciTech Connect

A reciprocating electric motor-pump assembly for lifting well fluid on downstroke of the motor pump assembly, the pump including a barrel below the motor having dual combined inlet and outlet valve means at the lower end thereof, the pump piston moving in the barrel having annular grooves therearound to prevent differential pressure sticking, the electric cable supplying the electric motor being tubular to vent the pump and prevent vacuum or gas lock, there being a packer about the valve barrel separating the outlet valve means thereabove from the inlet valve means therebelow and a packer above the motor about a production tubing including an upper standing valve.

Holm, D. R.

1985-10-22T23:59:59.000Z

116

Multi-port valve assembly  

DOE Patents (OSTI)

A multi-port fluid valve apparatus is used to control the flow of fluids through a plurality of valves and includes a web, which preferably is a stainless steel endless belt. The belt has an aperture therethrough and is progressed, under motor drive and control, so that its aperture is moved from one valve mechanism to another. Each of the valve mechanisms comprises a pair of valve blocks which are held in fluid-tight relationship against the belt. Each valve block consists of a block having a bore through which the fluid flows, a first seal surrounding the bore and a second seal surrounding the first seal, with the distance between the first and second seals being greater than the size of the belt aperture. In order to open a valve, the motor progresses the belt aperture to where it is aligned with the two bores of a pair of valve blocks, such alignment permitting a flow of the fluid through the valve. The valve is closed by movement of the belt aperture and its replacement, within the pair of valve blocks, by a solid portion of the belt.

Guggenheim, S. Frederic (Teaneck, NJ)

1986-01-01T23:59:59.000Z

117

Throttled Valve Cavitation and Erosion  

E-Print Network (OSTI)

The submitted manuscipt has been authored by a contmrctor of the US. Government under contract No. DE-AC05-840R21400. Accordingly, the U. S. Government retains a nonexclusive royalty-free license to publish or reproduce the published form of the contribution, or aflow others to do so, for US. Government pupose & 1. Background In November of 1988, Brunswick plant maintenance personnel discovered significant localized erosion of the valve body of a Unit I Residual Heat Removal (RHR) valve, 1-El 1-F017B (the maintenance was being performed to repair the valve stem and back seat). 1 The F017B valv'e is a 20-inch Rockwell angle globe valve that has been historically used to throttle RHR flow. Excessive throttling of the valve had resulted in cavitation-induced erosion damage to areas immediately downstream of the seat. Subsequent investigation indicated that erosion of valve bodies was a generic concern for the other RHR valves used in the same service (FO17A on Unit I and F017A and F017B on Unit 2). Brunswick personnel expanded the investigation to include another set of RHR valves that had also been used in throttling service. The F024A and F024B valves (from both Units), which are used for Suppression Pool Cooling, were also found to have been damaged by

Don Casada; Don Casada

1991-01-01T23:59:59.000Z

118

Micro-valve pump light valve display  

DOE Patents (OSTI)

In this invention, a flat panel display incorporates a plurality of micro-pump light valves (MLV`s) to form pixels for recreating an image. Each MLV consists of a dielectric drop sandwiched between substrates, at least one of which is transparent, a holding electrode for maintaining the drop outside a viewing area, and a switching electrode from accelerating the drop from a location within the holding electrode to a location within the viewing area. The substrates may further define non-wetting surface areas to create potential energy barriers to assist in controlling movement of the drop. The forces acting on the drop are quadratic in nature to provide a nonlinear response for increased image contrast. A crossed electrode structure can be used to activate the pixels whereby a large flat panel display is formed without active driver components at each pixel.

Lee, Yee-Chun

1991-01-15T23:59:59.000Z

119

Micro-valve pump light valve display  

DOE Patents (OSTI)

In this invention, a flat panel display incorporates a plurality of micro-pump light valves (MLV's) to form pixels for recreating an image. Each MLV consists of a dielectric drop sandwiched between substrates, at least one of which is transparent, a holding electrode for maintaining the drop outside a viewing area, and a switching electrode from accelerating the drop from a location within the holding electrode to a location within the viewing area. The substrates may further define non-wetting surface areas to create potential energy barriers to assist in controlling movement of the drop. The forces acting on the drop are quadratic in nature to provide a nonlinear response for increased image contrast. A crossed electrode structure can be used to activate the pixels whereby a large flat panel display is formed without active driver components at each pixel.

Lee, Yee-Chun.

1991-01-15T23:59:59.000Z

120

Micro-valve pump light valve display  

DOE Patents (OSTI)

A flat panel display incorporates a plurality of micro-pump light valves (MLV's) to form pixels for recreating an image. Each MLV consists of a dielectric drop sandwiched between substrates, at least one of which is transparent, a holding electrode for maintaining the drop outside a viewing area, and a switching electrode from accelerating the drop from a location within the holding electrode to a location within the viewing area. The sustrates may further define non-wetting surface areas to create potential energy barriers to assist in controlling movement of the drop. The forces acting on the drop are quadratic in nature to provide a nonlinear response for increased image contrast. A crossed electrode structure can be used to activate the pixels whereby a large flat panel display is formed without active driver components at each pixel.

Yeechun Lee.

1993-01-19T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Optimal time-resource allocation for activity-detection via multimodal sensing  

Science Conference Proceedings (OSTI)

The optimal allocation of measurements for activity-level detection in a wireless body area network (WBAN) for health-monitoring applications is considered. The WBAN with heterogeneous sensors is deployed in a simple star topology with the fusion center ...

Gautam Thatte; Viktor Rozgic; Ming Li; Sabyasachi Ghosh; Urbashi Mitra; Shri Narayanan; Murali Annavaram; Donna Spruijt-Metz

2009-04-01T23:59:59.000Z

122

Exploring time/resource trade-offs by solving dual scheduling problems with the ant colony optimization  

Science Conference Proceedings (OSTI)

Design space exploration during high-level synthesis is often conducted through ad hoc probing of the solution space using some scheduling algorithm. This is not only time consuming but also very dependent on designer's experience. We propose a novel ... Keywords: Design space exploration, ant colony optimization, instruction scheduling, max-min ant system

Gang Wang; Wenrui Gong; Brian Derenzi; Ryan Kastner

2007-09-01T23:59:59.000Z

123

Fast-acting valve and uses thereof  

SciTech Connect

A very fast acting valve capable of producing a very well-defined plug of gas suitable for filling a theta pinch vacuum vessel is given. The valve requires no springs, instead being stopped mainly by a nonlinear force. Thus, the valve is not subject to bouncing; and the ratio of the size of the valve housing to the size of the valve stem is smaller than it would be if springs were needed to stop the valve stem. Furthermore, the valve can be used for thousands of valve firings with no apparent valve damage.

Meyer, James A. (Espanola, NM)

1982-01-01T23:59:59.000Z

124

Performance Characteristics of an Isothermal Freeze Valve  

Science Conference Proceedings (OSTI)

This document discusses performance characteristics of an isothermal freeze valve. A freeze valve has been specified for draining the DWPF melter at the end of its lifetime. Two freeze valve designs have been evaluated on the Small Cylindrical Melter-2 (SCM-2). In order to size the DWPF freeze valve, the basic principles governing freeze valve behavior need to be identified and understood.

Hailey, A.E.

2001-08-22T23:59:59.000Z

125

Semi-active compressor valve  

SciTech Connect

A method and system for fine-tuning the motion of suction or discharge valves associated with cylinders of a reciprocating gas compressor, such as the large compressors used for natural gas transmission. The valve's primary driving force is conventional, but the valve also uses an electromagnetic coil to sense position of the plate (or other plugging element) and to provide an opposing force prior to impact.

Brun, Klaus (Helotes, TX); Gernentz, Ryan S. (San Antonio, TX)

2010-07-27T23:59:59.000Z

126

Semi-active compressor valve  

DOE Patents (OSTI)

A method and system for fine-tuning the motion of suction or discharge valves associated with cylinders of a reciprocating gas compressor, such as the large compressors used for natural gas transmission. The valve's primary driving force is conventional, but the valve also uses an electromagnetic coil to sense position of the plate (or other plugging element) and to provide an opposing force prior to impact.

Brun, Klaus (Helotes, TX); Gernentz, Ryan S. (San Antonio, TX)

2010-07-27T23:59:59.000Z

127

Streamline coal slurry letdown valve  

DOE Patents (OSTI)

A streamlined coal slurry letdown valve is featured which has a two-piece throat comprised of a seat and seat retainer. The two-piece design allows for easy assembly and disassembly of the valve. A novel cage holds the two-piece throat together during the high pressure letdown. The coal slurry letdown valve has long operating life as a result of its streamlined and erosion-resistance surfaces.

Platt, Robert J. (Dover, NJ); Shadbolt, Edward A. (Basking Ridge, NJ)

1983-01-01T23:59:59.000Z

128

Streamline coal slurry letdown valve  

DOE Patents (OSTI)

A streamlined coal slurry letdown valve is featured which has a two-piece throat comprised of a seat and seat retainer. The two-piece design allows for easy assembly and disassembly of the valve. A novel cage holds the two-piece throat together during the high pressure letdown. The coal slurry letdown valve has long operating life as a result of its streamlined and erosion-resistance surfaces. 5 figs.

Platt, R.J.; Shadbolt, E.A.

1983-11-08T23:59:59.000Z

129

Valve stem and packing assembly  

SciTech Connect

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

Wordin, John J. (Bingham County, ID)

1991-01-01T23:59:59.000Z

130

Valve stem and packing assembly  

DOE Patents (OSTI)

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

Wordin, J.J.

1991-09-03T23:59:59.000Z

131

Valve stem and packing assembly  

DOE Patents (OSTI)

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

Wordin, J.J.

1990-01-01T23:59:59.000Z

132

Real-Time Optimization Strategies for Building Systems Victor M. Zavala  

E-Print Network (OSTI)

the interactions between states and controls to optimize performance. The use of predictive models also makes systems. While di- verse studies have been reported [16, 11, 12, 21, 4, 29, 18, 26], traditional control the potential of changing this landscape. These predictive control-based tools enable the anticipation

133

Deterministic regression model and visual basic code for optimal forecasting of financial time series  

Science Conference Proceedings (OSTI)

A new, non-statistical method is presented for analysis of the past history and current evolution of economic and financial processes. The method is based on the sliding model approach using linear differential or difference equations applied to discrete ... Keywords: Optimal forecasting in finance, Sliding deterministic regression models

Alejandro Balbás; Beatriz Balbás; Inna Galperin; Efim Galperin

2008-11-01T23:59:59.000Z

134

Real-Time Obstacle Avoidance Method for Mobile Robots Based on a Modified Particle Swarm Optimization  

Science Conference Proceedings (OSTI)

A novel method for the robot path planning in dynamic environment is presented in this paper. Based on the analysis of visual modeling, the reason of premature convergence and diversity loss in PSO is explained, and a new modified algorithm is proposed ... Keywords: Obstacle Avoidance, Particle Swarm Optimization, path planning

Yuxin Zhao; Wei Zu

2009-04-01T23:59:59.000Z

135

Real-time optical micro-manipulation using optimized holograms generated on the GPU  

E-Print Network (OSTI)

Holographic optical tweezers allow the three dimensional, dynamic, multipoint manipulation of micron sized dielectric objects. Exploiting the massive parallel architecture of modern GPUs we can generate highly optimized holograms at video frame rate allowing the interactive micro-manipulation of 3D structures.

S. Bianchi; R. Di Leonardo

2009-07-23T23:59:59.000Z

136

DISCHARGE VALVE FOR GRANULAR MATERIAL  

DOE Patents (OSTI)

A gravity-red dispenser or valve is designed for discharging the fueled spherical elements used in a pebble bed reactor. The dispenser consists of an axially movable tube terminating under a hood having side walls with openings. When the tube is moved so that its top edge is above the tops of the side openings the elements will not flow. As the tube is moved downwardly, the elements flow into the hood through the side openings and over the top edge into the tube at an increasing rate as the tube is lowered further. The tube is spaced at all times from the hood and side walls a distance greater than the diameter of the largest element to prevent damaging of the elements when the dispenser is closed to flow. (AEC)

Stoughton, L.D.; Robinson, S.T.

1962-05-15T23:59:59.000Z

137

All metal valve structure for gas systems  

DOE Patents (OSTI)

A valve assembly with a resilient metal seat member is disclosed for providing a gas-tight seal in a gas handling system. The valve assembly also includes a valve element for sealing against the valve seat member; and an actuating means for operating the valve element. The valve seat member is a one-piece stainless steel ring having a central valve port and peripheral mounting flange, and an annular corrugation in between. A groove between the first and second ridges serves as a flexure zone during operation of the valve member and thus provides the seating pressure between the inner ridge or valve seat and the valve element. The outer annular ridge has a diameter less than said valve element to limit the seating motion of the valve element, preventing non-elastic deformation of the seat member.

Baker, Ray W. (Hamilton, OH); Pawlak, Donald A. (Centerville, OH); Ramey, Alford J. (Miamisburg, OH)

1984-11-13T23:59:59.000Z

138

Optimizing the extreme learning machine using harmony search for hydrologic time series forecasting  

Science Conference Proceedings (OSTI)

Lately, the research related to time series forecasting has been an area of considerable interest in different fields. It is very important to predict the behavior of the time series but it is not an easy task. Several models to aim this issue have been ... Keywords: extreme learning machine, harmony search, hybrid intelligent system, time series forecasting

Ivna Valença; Mêuser Valença

2012-08-01T23:59:59.000Z

139

Generic Mechanism of Optimal Energy Transfer Efficiency: A Scaling Theory of the Mean First Passage Time in Exciton Systems  

E-Print Network (OSTI)

An asymptotic scaling theory is presented using the conceptual basis of trapping-free subspace (i.e., orthogonal subspace) to establish the generic mechanism of optimal efficiency of excitation energy transfer (EET) in light-harvesting systems. Analogous to Kramers' turnover in classical rate theory, the enhanced efficiency in the weak damping limit and the suppressed efficiency in the strong damping limit define two asymptotic scaling regimes, which are interpolated to predict the functional form of optimal efficiency of the trapping-free subspace. In the presence of static disorder, the scaling law of transfer time with respect to dephasing rate changes from linear to square root, suggesting a weaker dependence on the environment. Though formulated in the context of EET, the analysis and conclusions apply in general to open quantum processes, including electron transfer, fluorescence emission, and heat conduction.

Wu, Jianlan; Silbey, Robert J

2013-01-01T23:59:59.000Z

140

Unsupervised parameter optimization for automated retention time alignment of severely shifted gas chromatographic data using the piecework alignment algorithm.  

Science Conference Proceedings (OSTI)

First, simulated chromatographic separations with declining retention time precision were used to study the performance of the piecewise retention time alignment algorithm and to demonstrate an unsupervised parameter optimization method. The average correlation coefficient between the first chromatogram and every other chromatogram in the data set was used to optimize the alignment parameters. This correlation method does not require a training set, so it is unsupervised and automated. This frees the user from needing to provide class information and makes the alignment algorithm more generally applicable to classifying completely unknown data sets. For a data set of simulated chromatograms where the average chromatographic peak was shifted past two neighboring peaks between runs, the average correlation coefficient of the raw data was 0.46 ± 0.25. After automated, optimized piecewise alignment, the average correlation coefficient was 0.93 ± 0.02. Additionally, a relative shift metric and principal component analysis (PCA) were used to independently quantify and categorize the alignment performance, respectively. The relative shift metric was defined as four times the standard deviation of a given peak’s retention time in all of the chromatograms, divided by the peak-width-at-base. The raw simulated data sets that were studied contained peaks with average relative shifts ranging between 0.3 and 3.0. Second, a “real” data set of gasoline separations was gathered using three different GC methods to induce severe retention time shifting. In these gasoline separations, retention time precision improved ~8 fold following alignment. Finally, piecewise alignment and the unsupervised correlation optimization method were applied to severely shifted GC separations of reformate distillation fractions. The effect of piecewise alignment on peak heights and peak areas is also reported. Piecewise alignment either did not change the peak height, or caused it to slightly decrease. The average relative difference in peak height after piecewise alignment was –0.20%. Piecewise alignment caused the peak areas to either stay the same, slightly increase, or slightly decrease. The average absolute relative difference in area after piecewise alignment was 0.15%.

Pierce, Karisa M.; Wright, Bob W.; Synovec, Robert E.

2007-02-02T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

"Optimal Market Grain Over Space and Time"* Nodir Adilov and Richard E. Schuler  

E-Print Network (OSTI)

generation facilities that could ultimately alter line flows, and therefore congestion -- the rationale for just in time manufacture, when the product's availability is essential for some customers

142

An optimal k-exclusion real-time locking protocol motivated by multi-GPU systems  

Science Conference Proceedings (OSTI)

Graphics processing units (GPUs) are becoming increasingly important in today's platforms as their growing generality allows for them to be used as powerful co-processors. In previous work, the authors showed that GPUs may be integrated into real-time ... Keywords: GPGPU, Global scheduling, Real-time systems, Semaphore protocols

Glenn A. Elliott; James H. Anderson

2013-03-01T23:59:59.000Z

143

On Optimal Prediction of Atmospheric Ekman Layer Fluctuations over Short Lead Times  

Science Conference Proceedings (OSTI)

Wind and temperature time series, sampled at 10 min intervals 250 and 600 m above the ground, are analyzed. For horizontal wind components and temperature forecasting, autoregressive integrated models of the type (p, 1, 0); p ? 4 provide the best ...

Karl J. Eidsvik

1981-12-01T23:59:59.000Z

144

On the Design and Optimization of a Quantum Polynomial-Time Attack on Elliptic Curve Cryptography  

Science Conference Proceedings (OSTI)

We consider a quantum polynomial-time algorithm which solves the discrete logarithm problem for points on elliptic curves over GF (2 m ). We improve over earlier algorithms by constructing an efficient ...

Donny Cheung; Dmitri Maslov; Jimson Mathew; Dhiraj K. Pradhan

2008-11-01T23:59:59.000Z

145

Multi-port valve  

DOE Patents (OSTI)

A multi-port valve is described for regulating, as a function of ambient air having varying wind velocity and wind direction in an open-field control area, the distribution of a fluid, particularly carbon dioxide (CO{sub 2}) gas, in a fluid distribution system so that the control area remains generally at an elevated fluid concentration or level of said fluid. The multi-port valve generally includes a multi-port housing having a plurality of outlets there through disposed in a first pattern of outlets and at least one second pattern of outlets, and a movable plate having a plurality of apertures extending there through disposed in a first pattern of apertures and at least one second pattern of apertures. The first pattern of apertures being alignable with the first pattern of outlets and the at least one second pattern of apertures being alignable with the second pattern of outlets. The first pattern of apertures has a predetermined orientation with the at least one second pattern of apertures. For an open-field control area subject to ambient wind having a low velocity from any direction, the movable plate is positioned to equally distribute the supply of fluid in a fluid distribution system to the open-field control area. For an open-field control area subject to ambient wind having a high velocity from a given direction, the movable plate is positioned to generally distribute a supply of fluid in a fluid distribution system to that portion of the open-field control area located upwind. 7 figs.

Lewin, K.F.

1997-04-15T23:59:59.000Z

146

Multi-port valve  

DOE Patents (OSTI)

A multi-port valve for regulating, as a function of ambient air having varying wind velocity and wind direction in an open-field control area, the distribution of a fluid, particularly carbon dioxide (CO.sub.2) gas, in a fluid distribution system so that the control area remains generally at an elevated fluid concentration or level of said fluid. The multi-port valve generally includes a multi-port housing having a plurality of outlets therethrough disposed in a first pattern of outlets and at least one second pattern of outlets, and a movable plate having a plurality of apertures extending therethrough disposed in a first pattern of apertures and at least one second pattern of apertures. The first pattern of apertures being alignable with the first pattern of outlets and the at least one second pattern of apertures being alignable with the second pattern of outlets. The first pattern of apertures has a predetermined orientation with the at least one second pattern of apertures. For an open-field control area subject to ambient wind having a low velocity from any direction, the movable plate is positioned to equally distribute the supply of fluid in a fluid distribution system to the open-field control area. For an open-field control area subject to ambient wind having a high velocity from a given direction, the movable plate is positioned to generally distribute a supply of fluid in a fluid distribution system to that portion of the open-field control area located upwind.

Lewin, Keith F. (Calverton, NY)

1997-04-15T23:59:59.000Z

147

Adaptive real-time methodology for optimizing energy-efficient computing  

DOE Patents (OSTI)

Dynamic voltage and frequency scaling (DVFS) is an effective way to reduce energy and power consumption in microprocessor units. Current implementations of DVFS suffer from inaccurate modeling of power requirements and usage, and from inaccurate characterization of the relationships between the applicable variables. A system and method is proposed that adjusts CPU frequency and voltage based on run-time calculations of the workload processing time, as well as a calculation of performance sensitivity with respect to CPU frequency. The system and method are processor independent, and can be applied to either an entire system as a unit, or individually to each process running on a system.

Hsu, Chung-Hsing; Feng, Wu-Chun

2013-01-29T23:59:59.000Z

148

Adaptive real-time methodology for optimizing energy-efficient computing  

DOE Patents (OSTI)

Dynamic voltage and frequency scaling (DVFS) is an effective way to reduce energy and power consumption in microprocessor units. Current implementations of DVFS suffer from inaccurate modeling of power requirements and usage, and from inaccurate characterization of the relationships between the applicable variables. A system and method is proposed that adjusts CPU frequency and voltage based on run-time calculations of the workload processing time, as well as a calculation of performance sensitivity with respect to CPU frequency. The system and method are processor independent, and can be applied to either an entire system as a unit, or individually to each process running on a system.

Hsu, Chung-Hsing (Los Alamos, NM); Feng, Wu-Chun (Blacksburg, VA)

2011-06-28T23:59:59.000Z

149

Reducing Wait Times Through Operations Research: Optimizing the Use of Surge Capacity  

E-Print Network (OSTI)

and · there is significant variability over time in the demand for health care services. By capacity, we mean the maximum, University of British Columbia July 20, 2007 1 #12;Abstract Widespread public demand for improved access services arise because: · capacity does not match demand, · capacity or demand is not well managed

Puterman, Martin L.

150

Platelet thrombosis in cardiac-valve prostheses  

SciTech Connect

The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day study in the dog model was similar (< 1% if injected In-111 platelets = 5 billion platelets). As the fibrous ingrowth covered the sewing ring, the thrombus formation decreased significantly. Only a small amount of thrombus was found on the leaflets at one month in both the dog and calf models. 38 refs., 9 figs., 5 tabs.

Dewanjee, M.K.

1989-01-01T23:59:59.000Z

151

Valves - current operating experience of slurry valves (block and letdown) in coal liquefaction processes. Third quarter report  

Science Conference Proceedings (OSTI)

This paper summarizes the recent letdown and block valve experience in the liquefaction pilot plants. Also included is a brief description of the research and development activities on valves which are conducted in supporting laboratories. The purpose of the summary is to concentrate on critical component problems common to all liquefaction plants, to avoid duplication of efforts, and to help provide timely solutions to the valve problems. The main source of information used in this paper is the Minutes of the Critical Component and Materials Meeting which is sponsored by the Office of Coal Processing, Fossil Energy, Department of Energy. Other sources of information such as the technical progress reports are also included based on availability and relevance to topics covered in this paper. It is intended that this report will be followed by updates as pertinent information concerning valves becomes available. In the subsequent sections of this paper a brief outline of past valve studies is given as background material followed by a summary of the most recent valve operating experience at the liquefaction plants.

NONE

1996-07-01T23:59:59.000Z

152

OPTIMAL STRATEGIES FOR CONTINUOUS GRAVITATIONAL WAVE DETECTION IN PULSAR TIMING ARRAYS  

Science Conference Proceedings (OSTI)

Supermassive black hole binaries (SMBHBs) are expected to emit a continuous gravitational wave signal in the pulsar timing array (PTA) frequency band (10{sup -9} to 10{sup -7} Hz). The development of data analysis techniques aimed at efficient detection and characterization of these signals is critical to the gravitational wave detection effort. In this paper, we leverage methods developed for LIGO continuous wave gravitational searches and explore the use of the F-statistic for such searches in pulsar timing data. Babak and Sesana have used this approach in the context of PTAs to show that one can resolve multiple SMBHB sources in the sky. Our work improves on several aspects of prior continuous wave search methods developed for PTA data analysis. The algorithm is implemented fully in the time domain, which naturally deals with the irregular sampling typical of PTA data and avoids spectral leakage problems associated with frequency domain methods. We take into account the fitting of the timing model and have generalized our approach to deal with both correlated and uncorrelated colored noise sources. We also develop an incoherent detection statistic that maximizes over all pulsar-dependent contributions to the likelihood. To test the effectiveness and sensitivity of our detection statistics, we perform a number of Monte Carlo simulations. We produce sensitivity curves for PTAs of various configurations and outline an implementation of a fully functional data analysis pipeline. Finally, we present a derivation of the likelihood maximized over the gravitational wave phases at the pulsar locations, which results in a vast reduction of the search parameter space.

Ellis, J. A.; Siemens, X.; Creighton, J. D. E. [Center for Gravitation, Cosmology and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States)

2012-09-10T23:59:59.000Z

153

Variance Optimal Hedging for discrete time processes with independent increments. Application to Electricity Markets  

E-Print Network (OSTI)

We consider the discretized version of a (continuous-time) two-factor model introduced by Benth and coauthors for the electricity markets. For this model, the underlying is the exponent of a sum of independent random variables. We provide and test an algorithm, which is based on the celebrated Foellmer-Schweizer decomposition for solving the mean-variance hedging problem. In particular, we establish that decomposition explicitely, for a large class of vanilla contingent claims. Interest is devoted in the choice of rebalancing dates and its impact on the hedging error, regarding the payoff regularity and the non stationarity of the log-price process.

Goutte, Stéphane; Russo, Francesco

2012-01-01T23:59:59.000Z

154

Noninvasive valve monitor using alternating electromagnetic field  

SciTech Connect

One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

Eissenberg, David M. (Oak Ridge, TN); Haynes, Howard D. (Knoxville, TN); Casada, Donald A. (Knoxville, TN)

1993-01-01T23:59:59.000Z

155

Optimization of temperature-time sequences in reaction-regeneration cycles--Application to the isomerization of cis-butene  

SciTech Connect

The isomerization of cis-butene on a silica-alumina catalyst, in successive and uninterrupted reaction-regeneration cycles, in an isothermal integral fixed-bed reactor, has been simulated and experimentally studied. In the program for simulation, the following kinetic equations were used: the main reaction, deactivation, and reactivation. The simultaneous optimization of reaction and regeneration steps, with the aim of maximizing the apparent production rate of 1-butene or trans-butene, has been studied. The reaction was operated following a temperature-time sequence. The regeneration consisted of the combination of a step of stripping treatment with an inert gas and of a step of coke combustion. The results of simulation have been experimentally proven in automated reaction-regeneration equipment, in which the optimum conditions of both steps have been used.

Gayubo, A.G.; Arandes, J.M.; Aguayo, A.T.; Olazar, M.; Bilbao, J. (Univ. del Pais Vasco, Bilbao (Spain). Dept. de Ingenieria Quimica)

1993-11-01T23:59:59.000Z

156

Flow Characteristics Analysis of Widows' Creek Type Control Valve for Steam Turbine Control  

Science Conference Proceedings (OSTI)

The steam turbine converts the kinetic energy of steam to mechanical energy of rotor blades in the power conversion system of fossil and nuclear power plants. The electric output from the generator of which the rotor is coupled with that of the steam turbine depends on the rotation velocity of the steam turbine bucket. The rotation velocity is proportional to the mass flow rate of steam entering the steam turbine through valves and nozzles. Thus, it is very important to control the steam mass flow rate for the load following operation of power plants. Among various valves that control the steam turbine, the control valve is most significant. The steam flow rate is determined by the area formed by the stem disk and the seat of the control valve. While the ideal control valve linearly controls the steam mass flow rate with its stem lift, the real control valve has various flow characteristic curves pursuant to the stem lift type. Thus, flow characteristic curves are needed to precisely design the control valves manufactured for the operating conditions of nuclear power plants. OMEGA (Optimized Multidimensional Experiment Geometric Apparatus) was built to experimentally study the flow characteristics of steam flowing inside the control valve. The Widows' Creek type control valve was selected for reference. Air was selected as the working fluid in the OMEGA loop to exclude the condensation effect in this simplified approach. Flow characteristic curves were plotted by calculating the ratio of the measured mass flow rate versus the theoretical mass flow rate of the air. The flow characteristic curves are expected to be utilized to accurately design and operate the control valve for fossil as well as nuclear plants. (authors)

Yoo, Yong H.; Sohn, Myoung S.; Suh, Kune Y. [PHILOSOPHIA, Inc., Seoul National University, San 56-1 Sillim-dong, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)

2006-07-01T23:59:59.000Z

157

Lost-motion valve actuator  

SciTech Connect

A lost-motion valve actuator is described for a bore closure valve employed in a well bore, comprising: operating connector means adapted to move the bore closure valve between open and closed positions through longitudinal movement of the operating connector means. The operating connector means comprises an operating connector and a connector insert defining a recess therebetween; locking dog means comprising at least one locking dog received in the recess and spring biasing means adapted to urge at least one locking dog radially inwardly; and mandrel means slidably received within the operating connector means and including dog slot means associated therewith. The dog slot means comprises an annular slot on the exterior of the mandrel means adapted to lockingly receive at least one inwardly biased locking dog when proximate thereto, whereby longitudinal movement of the mandrel means is transmitted to the operating connector means.

Burris, W.J. III; Ringgenberg, P.D.

1987-04-07T23:59:59.000Z

158

Valve for controlling flow of cryogenic fluid  

DOE Patents (OSTI)

A valve is provided for accurately controlling the flow of cryogenic fluids such as liquid nitrogen. The valve comprises a combination of disc and needle valves affixed to a valve stem in such a manner that the disc and needle are free to rotate about the stem, but are constrained in lateral and vertical movements. This arrangement provides accurate and precise fluid flow control and positive fluid isolation.

Knapp, P.A.

1995-12-31T23:59:59.000Z

159

Microfluidic Polymer Valves - Energy Innovation Portal  

No electrical power is dissipated into the fluid during valve operation. The microvalve dielectric strength is comparable to glass.

160

Experiences and Attributes of Successful Valve Teams  

Science Conference Proceedings (OSTI)

Recently, a number of utilities have found that an effective approach to improve valve performance and reliability is to develop specialized cross-disciplinary teams that have the responsibility for a specific valve or valve types throughout the plant or utility. This report describes the composition, size, and functions of the different types of valve teams studied and provides a myriad of success stories and lessons learned regarding their employment throughout the nuclear power industry.

2000-12-20T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

TWO-WAY FREEZE VALVE  

DOE Patents (OSTI)

A valve for closing off the flow of radioactive and corrosive gases and liquids or mixtures thereof and forming a leak tight barrier is described. This valve has no mechanical moving parts which would require design to close tolerances and retention of the usual seal tighthess. Instead, there is provided a cavity in which a fusible metal is contained. Heating and cooling are provided to exercise control over the state of the metal. Baffle chambers are utilized to separate the molten fusible metal from the gas or liquid which is being passed through and return the molten metal to its cavity.

Lantz, K.D.; Clark, P.M.

1960-01-01T23:59:59.000Z

162

A Thermal Sensation Index for Real-Time Tuning and Energy-Optimal Control of HVAC Systems  

E-Print Network (OSTI)

In this paper we discuss and develop a thermal comfort index that addresses the limitations of applying thermal comfort indices to control applications. The derivation closely follows the derivation of PMV, but certain changes and simplifications make the index an explicit, linearly parameterized function of environmental variables. We show that the differences between the derivation of this index and the derivation of PMV do not reduce the accuracy of the index in comparison to PMV. Since this index is linearly parameterized, the parameters can be quickly and efficiently tuned in real time to reflect the thermal sensation of the specific occupant. Parameter tuning makes it possible to accurately predict the thermal sensation of the occupant without exact knowledge of the activity level or clothing insulation of the occupant when these two quantities are known to be constant. Additionally, the tuning process makes the thermal sensation prediction relatively insensitive to sensor location because biases and scaling errors are absorbed by the estimated parameters. Real-time parameter tuning is demonstrated experimentally for a seated, stationary occupant. The feasibility of using variable air flow and variable heat flow to regulate the thermal sensation index in a way that minimizes power consumption is investigated. The simplified index provides a quantitative means for determining the most energy efficient comfortable conditions. The analysis demonstrates that for low to moderate outdoor relative humidity there is an energy optimal combination of air flow and heat flow.

Federspiel, C. C.; Norford, L.

1992-05-01T23:59:59.000Z

163

Optimal Decision Making and the Value of Information in a Time-Dependent Version of the Cost-Loss Ratio Situation  

Science Conference Proceedings (OSTI)

A time-dependent version of the cost-loss ratio situation is described and the optimal use and economic value of meteorological information are investigated in this decision-making problem. The time-dependent situation is motivated by a decision ...

Allan H. Murphy; Qian Ye

1990-04-01T23:59:59.000Z

164

Valve for fuel pin loading system  

DOE Patents (OSTI)

A cyclone valve surrounds a wall opening through which cladding is projected. An axial valve inlet surrounds the cladding. Air is drawn through the inlet by a cyclone stream within the valve. An inflatable seal is included to physically engage a fuel pin subassembly during loading of fuel pellets.

Christiansen, D.W.

1984-01-01T23:59:59.000Z

165

Valve test program: response to TMI  

Science Conference Proceedings (OSTI)

The Electric Power Research Institute (EPRI) pressurized-water reactor (PWR) safety and relief valve test program was speedily organized to assess valve operability after a pressurizer relief valve malfunctioned at Three Mile Island (TMI). Comprehensive full-scale testing at several facilities validated the basic designs in use today. 2 figures.

Lihach, N.; Bilanin, W.; Carey, J.

1983-05-01T23:59:59.000Z

166

Valve for fuel pin loading system  

DOE Patents (OSTI)

A cyclone valve surrounds a wall opening through which cladding is projected. An axial valve inlet surrounds the cladding. Air is drawn through the inlet by a cyclone stream within the valve. An inflatable seal is included to physically engage a fuel pin subassembly during loading of fuel pellets.

Christiansen, David W. (Kennewick, WA)

1985-01-01T23:59:59.000Z

167

The dosimetric impact of inversely optimized arc radiotherapy plan modulation for real-time dynamic MLC tracking delivery  

SciTech Connect

Purpose: Real-time dynamic multileaf collimator (MLC) tracking for management of intrafraction tumor motion can be challenging for highly modulated beams, as the leaves need to travel far to adjust for target motion perpendicular to the leaf travel direction. The plan modulation can be reduced by using a leaf position constraint (LPC) that reduces the difference in the position of adjacent MLC leaves in the plan. The purpose of this study was to investigate the impact of the LPC on the quality of inversely optimized arc radiotherapy plans and the effect of the MLC motion pattern on the dosimetric accuracy of MLC tracking delivery. Specifically, the possibility of predicting the accuracy of MLC tracking delivery based on the plan modulation was investigated. Methods: Inversely optimized arc radiotherapy plans were created on CT-data of three lung cancer patients. For each case, five plans with a single 358 deg. arc were generated with LPC priorities of 0 (no LPC), 0.25, 0.5, 0.75, and 1 (highest possible LPC), respectively. All the plans had a prescribed dose of 2 Gy x 30, used 6 MV, a maximum dose rate of 600 MU/min and a collimator angle of 45 deg. or 315 deg. To quantify the plan modulation, an average adjacent leaf distance (ALD) was calculated by averaging the mean adjacent leaf distance for each control point. The linear relationship between the plan quality [i.e., the calculated dose distributions and the number of monitor units (MU)] and the LPC was investigated, and the linear regression coefficient as well as a two tailed confidence level of 95% was used in the evaluation. The effect of the plan modulation on the performance of MLC tracking was tested by delivering the plans to a cylindrical diode array phantom moving with sinusoidal motion in the superior-inferior direction with a peak-to-peak displacement of 2 cm and a cycle time of 6 s. The delivery was adjusted to the target motion using MLC tracking, guided in real-time by an infrared optical system. The dosimetric results were evaluated using gamma index evaluation with static target measurements as reference. Results: The plan quality parameters did not depend significantly on the LPC (p {>=} 0.066), whereas the ALD depended significantly on the LPC (p < 0.001). The gamma index failure rate depended significantly on the ALD, weighted to the percentage of the beam delivered in each control point of the plan (ALD{sub w}) when MLC tracking was used (p < 0.001), but not for delivery without MLC tracking (p {>=} 0.342). The gamma index failure rate with the criteria of 2% and 2 mm was decreased from > 33.9% without MLC tracking to <31.4% (LPC 0) and <2.2% (LPC 1) with MLC tracking. Conclusions: The results indicate that the dosimetric robustness of MLC tracking delivery of an inversely optimized arc radiotherapy plan can be improved by incorporating leaf position constraints in the objective function without otherwise affecting the plan quality. The dosimetric robustness may be estimated prior to delivery by evaluating the ALD{sub w} of the plan.

Falk, Marianne; Larsson, Tobias; Keall, Paul; Chul Cho, Byung; Aznar, Marianne; Korreman, Stine; Poulsen, Per; Munck af Rosenschoeld, Per [Radiation Medicine Research Center, Department of Radiation Oncology - 3994, Rigshospitalet, Blegdamsvej 9, DK - 2100 Copenhagen (Denmark) and Niels Bohr Institute, University of Copenhagen (Denmark); Radiation Medicine Research Center, Department of Radiation Oncology, Rigshospitalet, Copenhagen University Hospital (Denmark); Radiation Physics Laboratory, Sydney Medical School, University of Sydney (Australia); Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Radiation Medicine Research Center, Department of Radiation Oncology, Rigshospitalet, Copenhagen University Hospital, Denmark and Niels Bohr Institute, University of Copenhagen (Denmark); Radiation Medicine Research Center, Department of Radiation Oncology, Rigshospitalet, Copenhagen University Hospital (Denmark); Niels Bohr Institute, University of Copenhagen (Denmark) and Department of Science, Systems and Models, Roskilde University (Denmark); Department of Oncology, Aarhus University Hospital (Denmark); Radiation Medicine Research Center, Department of Radiation Oncology, Rigshospitalet, Copenhagen University Hospital (Denmark) and Niels Bohr Institute, University of Copenhagen (Denmark)

2012-03-15T23:59:59.000Z

168

Hydraulic servo control spool valve  

DOE Patents (OSTI)

A servo operated spool valve having a fixed sleeve and axially movable spool. The sleeve is machined in two halves to form a long, narrow tapered orifice slot across which a transverse wall of the spool is positioned. The axial position of the spool wall along the slot regulates the open orifice area with extreme precision.

Miller, Donald M. (Sunnyside, WA)

1983-01-01T23:59:59.000Z

169

Valve assembly for inflatable packer  

Science Conference Proceedings (OSTI)

This patent describes a valve assembly for controlling the flow of fluid from within casing into a bladder element of an inflatable packer for use in a wellbore. The bladder element has bladder port means. The valve assembly is mountable within a single cavity in a body member in the wall of casing or a casing coupling. The body member has casing port means communicating with the cavity for communicating casing fluid to the bladder port means so that the casing fluid can flow through the bladder port means to inflate the bladder element and the body member having overpressure port means communicating with the cavity for communicating part of the fluid flowing into the bladder element back to the cavity and to the valve assembly. The valve assembly comprises: control piston means movably mounted within the cavity, restraint means for insuring that the control piston means initially moves only when the pressure of the casing fluid reaches a predetermined level, and closing piston means movably mounted within the cavity and responsive to the pressure of the fluid in the bladder element, and the control piston means and the closing piston movable about stem means disposed in the cavity.

Stringfellow, W.D.

1987-12-08T23:59:59.000Z

170

Valve Application, Maintenance, and Repair Guide  

Science Conference Proceedings (OSTI)

The Valve Application, Maintenance, and Repair Guide is a two-volume series that provides a generic overview of valve application, selection, maintenance, and repair. Volume 1 of the series is a comprehensive reference on the application and use of valves that provides guidance on the selection of specific types of valves on the basis of functional and system requirements. This document is based on an earlier EPRI document (NP-6516, Guide for the Application and Use of Valves in Power Plant Systems). Ext...

1999-05-07T23:59:59.000Z

171

Change-over valve for air suspension  

Science Conference Proceedings (OSTI)

A change-over valve is described for an air suspension interposed between a main air chamber formed to surround a shock absorber provided with a piston rod and an auxiliary air chamber, comprising: a valve base having a first hole through which the piston rod extends and a second hole into which a valve body is inserted; the valve body disposed in the second hole; a holder disposed in the second hole; and means removably fixed to the piston rod extending through the first hole to connect the piston rod with the valve base while preventing the holder from falling out.

Buma, S.

1987-04-28T23:59:59.000Z

172

Hydraulically actuated fuel injector including a pilot operated spool valve assembly and hydraulic system using same  

DOE Patents (OSTI)

The present invention relates to hydraulic systems including hydraulically actuated fuel injectors that have a pilot operated spool valve assembly. One class of hydraulically actuated fuel injectors includes a solenoid driven pilot valve that controls the initiation of the injection event. However, during cold start conditions, hydraulic fluid, typically engine lubricating oil, is particularly viscous and is often difficult to displace through the relatively small drain path that is defined past the pilot valve member. Because the spool valve typically responds slower than expected during cold start due to the difficulty in displacing the relatively viscous oil, accurate start of injection timing can be difficult to achieve. There also exists a greater difficulty in reaching the higher end of the cold operating speed range. Therefore, the present invention utilizes a fluid evacuation valve to aid in displacement of the relatively viscous oil during cold start conditions.

Shafer, Scott F. (Morton, IL)

2002-01-01T23:59:59.000Z

173

Measure it, See it, Manage it: Using Real Time Data to Benchmark,Optimize, and Sustain System Energy Efficiency  

SciTech Connect

Even after years of training and awareness building at thestate and national level, industrial cross-cutting systems (motor-driven,steam, process heating) continue to offer significant opportunities forenergy savings. The US Department of Energy estimates these remainingsavings at more than 7 percent of all industrial energy use. This paperpresents a different approach to promoting industrial system energyefficiency -- providing plant personnel with ready access to data uponwhich to base energy management decisions.In 2005, a Del Monte Foodsfruit processing plant in Modesto, California worked with LawrenceBerkeley National Laboratory (LBNL)to specify and purchase permanentinstrumentation for monitoring their compressed air system. This work,completed as part of a demonstration project under a State TechnologiesAdvancement Collaborative (STAC) grant, was designed to demonstrate theeffectiveness of enterprise energy management (EEM), which is predicatedon the assumption that the energy efficiency of existing, cross-cuttingindustrial systems (motor-driven, steam) can be improved by providingmanagement and operating personnel with real-time data on energy use. Theinitial STAC grant provided for the installation and some initialanalyses, but did not address the larger issue of integrating these newdata into an ongoing energy management program for the compressed airsystem.The California Energy Commission (CEC) decided to support furtheranalysis to identify potential for air system optimization. Through theCEC's Energy in Agriculture Program, a compressed air system audit wasperformed by Tom Taranto to: Measure and document the system's baselineand CASE Index of present operation; Establish methods to sustain anongoing CASE Index measure of performance; Use AIRMaster+ to analyzesupply side performance as compared to the CASE Index; Identify demandside opportunities for efficiency and performance improvement; Assesssupply / demand balance and energy reduction opportunities; Evaluate thepresent air compressor control strategy and potential improvement, andCollect data to benchmark parameters for compressed air systems atsimilar facilities.This paper addresses the benefits and limitations ofboth continuous and targeted measurement in benchmarking, optimizing, andsustaining an efficient compressed air system. Included are methods usedin applying both of these measurements to a complex industrial system.Further, this paper will describe the results of these additionalanalyses and the plant response to them.

Taranto, Thomas; McKane, Aimee; Amon, Ricardo; Maulhardt, Michael

2007-07-02T23:59:59.000Z

174

Measure it, See it, Manage it: Using Real Time Data to Benchmark,Optimize, and Sustain System Energy Efficiency  

SciTech Connect

Even after years of training and awareness building at thestate and national level, industrial cross-cutting systems (motor-driven,steam, process heating) continue to offer significant opportunities forenergy savings. The US Department of Energy estimates these remainingsavings at more than 7 percent of all industrial energy use. This paperpresents a different approach to promoting industrial system energyefficiency -- providing plant personnel with ready access to data uponwhich to base energy management decisions.In 2005, a Del Monte Foodsfruit processing plant in Modesto, California worked with LawrenceBerkeley National Laboratory (LBNL)to specify and purchase permanentinstrumentation for monitoring their compressed air system. This work,completed as part of a demonstration project under a State TechnologiesAdvancement Collaborative (STAC) grant, was designed to demonstrate theeffectiveness of enterprise energy management (EEM), which is predicatedon the assumption that the energy efficiency of existing, cross-cuttingindustrial systems (motor-driven, steam) can be improved by providingmanagement and operating personnel with real-time data on energy use. Theinitial STAC grant provided for the installation and some initialanalyses, but did not address the larger issue of integrating these newdata into an ongoing energy management program for the compressed airsystem.The California Energy Commission (CEC) decided to support furtheranalysis to identify potential for air system optimization. Through theCEC's Energy in Agriculture Program, a compressed air system audit wasperformed by Tom Taranto to: Measure and document the system's baselineand CASE Index of present operation; Establish methods to sustain anongoing CASE Index measure of performance; Use AIRMaster+ to analyzesupply side performance as compared to the CASE Index; Identify demandside opportunities for efficiency and performance improvement; Assesssupply / demand balance and energy reduction opportunities; Evaluate thepresent air compressor control strategy and potential improvement, andCollect data to benchmark parameters for compressed air systems atsimilar facilities.This paper addresses the benefits and limitations ofboth continuous and targeted measurement in benchmarking, optimizing, andsustaining an efficient compressed air system. Included are methods usedin applying both of these measurements to a complex industrial system.Further, this paper will describe the results of these additionalanalyses and the plant response to them.

Taranto, Thomas; McKane, Aimee; Amon, Ricardo; Maulhardt, Michael

2007-07-02T23:59:59.000Z

175

2010 - Optimization Online  

E-Print Network (OSTI)

Minimum wight Topology optimization subject to unsteady heat equation and space-time pointwise ... Optimal adaptive control of cascading power grid failures

176

The Optimization of Control Parameters for VAV HVAC System Commissioning  

E-Print Network (OSTI)

One of the technical subjects in commissioning for HVAC system is to enhance control performance and time efficiency, while the tuning of the optimal parameters to control HVAC system takes much time and labor in particular. Therefore, we propose a kind of commissioning technique as follows. We identified the dynamic characteristics of components of an actual VAV HVAC system such as rooms, VAV dampers, two way valves and chilled water coils, and verified the behaviors of the models and choose the optimal control parameters on a personal computer. Then adopting them for the actual system, we verified the control performance. Through the procedure, we showed the possibility of off-site and off-line control parameter tuning to reduce the cost and time at on-site and in on-line using the measured data in a real HVAC system.

Song, S.; Maehara, K.; Sagara, N.

2006-01-01T23:59:59.000Z

177

A LARGE BAKEABLE VACUUM VALVE  

SciTech Connect

The development and design of a large bakeable valve based on a unique seat arrangement and a novel motion seal are described. The seat sealing is accomplished through the use of high pressure fluid actuation of an annular pinch gasket. Experimental data on seat closure performance, and the specific design features to achieve successful closures, are presented. The bakeable motion seal utilizes a stainless steel bellows sleeving over an inner concentric actuating shaft. This shaft is bent at 90 deg to the axis of rotation and is free to rotate relative to the bellows. There is no apparent size limitation to this type of actuation. The design of a 10-inch gate valve utilizing these principles is described. (auth)

Batzer, T.H.

1959-08-01T23:59:59.000Z

178

Enhancement of spin-dependent scattering and improvement of microstructure in spin valves by delayed deposition  

Science Conference Proceedings (OSTI)

Si/Ta/Co/Cu/CoFeMn (or NiO) spin valves were prepared by a delayed sputtering procedure, in which depositions of Ta and followed layers were intervened by 1 h. The spin valves are found to have better coherent growth with stronger (111) preferred orientations in Co and Cu layers, compared with the traditional continuous method. At the same time, the giant magnetoresistance ratio and spin-dependent scattering are enhanced by a factor of 20%-30%. These results indicate that the coherent growth and the (111) preferred orientation can enhance the spin-dependent scattering of spin valves.

Yang, D.Z.; Wang, L.; Yang, X.J.; Zhou, S.M.; Wu, X.S.; Du, J.; Hu, A.; Zhang, X.X. [Surface Physics Laboratory (State Key Laboratory) and Department of Physics, Fudan University, Shanghai 200433 (China) and Department of Physics, Southeast University, Nanjing 210096 (China); Surface Physics Laboratory (State Key Laboratory) and Department of Physics, Fudan University, Shanghai 200433 (China); National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Department of Physics, Hong Kong University of Science and Technology, Kowloon, Hong Kong (China)

2005-06-20T23:59:59.000Z

179

International Steam Turbine Valve Metallurgy Guide  

Science Conference Proceedings (OSTI)

This report reviews the state of the art in materials usage for steam turbine valves manufactured and used in Europe and looks at materials options for the higher-temperature applications now being considered for advanced high-efficiency power plants. The emphasis is on valves for extreme service conditions (high temperatures, pressures, and flow rates), of which bypass valves represent a good example. Some consideration is also given to degradation and failure mechanisms. In focusing on practices outsid...

2011-09-27T23:59:59.000Z

180

Propellant actuated nuclear reactor steam depressurization valve  

DOE Patents (OSTI)

A nuclear fission reactor combined with a propellant actuated depressurization and/or water injection valve is disclosed. The depressurization valve releases pressure from a water cooled, steam producing nuclear reactor when required to insure the safety of the reactor. Depressurization of the reactor pressure vessel enables gravity feeding of supplementary coolant water through the water injection valve to the reactor pressure vessel to prevent damage to the fuel core.

Ehrke, Alan C. (San Jose, CA); Knepp, John B. (San Jose, CA); Skoda, George I. (Santa Clara, CA)

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
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181

Improved valve and dash-pot assembly  

DOE Patents (OSTI)

A dash-pot valve comprises a cylinder submerged in the fluid of a housing and have a piston attached to a plunger projecting into the path of closing movement of a pivotal valve member. A vortex chamber in said cylinder is provided with targentially directed inlets to generate vortex flow upon retraction of said plunger and effect increasing resistance against said piston to progressively retard the closing rate of said valve member toward its seat.

Chang, S.C.

1985-04-23T23:59:59.000Z

182

Valve and dash-pot assembly  

DOE Patents (OSTI)

A dash-pot valve comprising a cylinder submerged in the fluid of a housing and having a piston attached to a plunger projecting into the path of closing movement of a pivotal valve member. A vortex chamber in said cylinder is provided with tangentially directed inlets to generate vortex flow upon retraction of said plunger and effect increasing resistance against said piston to progressively retard the closing rate of said valve member toward its seat.

Chang, Shih-Chih (Richland, WA)

1986-01-01T23:59:59.000Z

183

An approach for modeling the valve train system to control the homogeneous combustion in a compression ignition engine  

Science Conference Proceedings (OSTI)

This paper presents an approach for modeling the valve train system to obtain a homogeneous charge compression ignition (HCCI) engine from a gasoline engine. The HCCI engines use different indirect strategies to control the start of the combustion. The ... Keywords: exhaust gas recirculation, homogeneous charge compression ignition, variable valve timing

Radu Cosgarea; Corneliu Cofaru; Mihai Aleonte; Maria Luminita Scutaru; Liviu Jelenschi; Gabriel Sandu

2011-04-01T23:59:59.000Z

184

IMPROVEMENTS IN OR RELATING TO VALVED DUCTING  

SciTech Connect

A coaxial valved ducting is designed for fluid flow to and from a heat exchanger. The ducting comprises an inner pipe for flow of hot fluid, an outer pipe providing an annular passage for the countercurrent flow of cool fluid, a butterfly valve in the inner pipe, peripherally spaced longitudinal ribs joining the two pipes in the region of the valve, an extension of the outer pipe, and a butterfly or poppet valve associated with the extension. the inner pipe communicates with the heat exchanger by means of an extension through the outer pipe wall. (D.L.C.)

Blackburn, G.; Long, E.

1962-05-30T23:59:59.000Z

185

Steam distribution and energy delivery optimization using wireless sensors  

Science Conference Proceedings (OSTI)

The Extreme Measurement Communications Center at Oak Ridge National Laboratory (ORNL) explores the deployment of a wireless sensor system with a real-time measurement-based energy efficiency optimization framework in the ORNL campus. With particular focus on the 12-mile long steam distribution network in our campus, we propose an integrated system-level approach to optimize the energy delivery within the steam distribution system. We address the goal of achieving significant energy-saving in steam lines by monitoring and acting on leaking steam valves/traps. Our approach leverages an integrated wireless sensor and real-time monitoring capabilities. We make assessments on the real-time status of the distribution system by mounting acoustic sensors on the steam pipes/traps/valves and observe the state measurements of these sensors. Our assessments are based on analysis of the wireless sensor measurements. We describe Fourier-spectrum based algorithms that interpret acoustic vibration sensor data to characterize flows and classify the steam system status. We are able to present the sensor readings, steam flow, steam trap status and the assessed alerts as an interactive overlay within a web-based Google Earth geographic platform that enables decision makers to take remedial action. We believe our demonstration serves as an instantiation of a platform that extends implementation to include newer modalities to manage water flow, sewage and energy consumption.

Olama, Mohammed M [ORNL; Allgood, Glenn O [ORNL; Kuruganti, Phani Teja [ORNL; Sukumar, Sreenivas R [ORNL; Djouadi, Seddik M [ORNL; Lake, Joe E [ORNL

2011-01-01T23:59:59.000Z

186

Application of Time-Lapse Seismic Monitoring for the Control and Optimization of CO2 Enhanced Oil Recovery Operations  

SciTech Connect

This project, 'Application of Time-Lapse Seismic Monitoring for the Control and Optimization of CO{sub 2} Enhanced Oil Recovery Operations', investigated the potential for monitoring CO{sub 2} floods in carbonate reservoirs through the use of standard p-wave seismic data. This primarily involved the use of 4D seismic (time lapse seismic) in an attempt to observe and map the movement of the injected CO{sub 2} through a carbonate reservoir. The differences between certain seismic attributes, such as amplitude, were used for this purpose. This technique has recently been shown to be effective in CO{sub 2} monitoring in Enhanced Oil Recovery (EOR) projects, such as Weyborne. This study was conducted in the Charlton 30/31 field in the northern Michigan Basin, which is a Silurian pinnacle reef that completed its primary production in 1997 and was scheduled for enhanced oil recovery using injected CO{sub 2}. Prior to injection an initial 'Base' 3D survey was obtained over the field and was then processed and interpreted. CO{sub 2} injection within the main portion of the reef was conducted intermittently during 13 months starting in August 2005. During this time, 29,000 tons of CO{sub 2} was injected into the Guelph formation, historically known as the Niagaran Brown formation. By September 2006, the reservoir pressure within the reef had risen to approximately 2000 lbs and oil and water production from the one producing well within the field had increased significantly. The determination of the reservoir's porosity distribution, a critical aspect of reservoir characterization and simulation, proved to be a significant portion of this project. In order to relate the differences observed between the seismic attributes seen on the multiple 3D seismic surveys and the actual location of the CO{sub 2}, a predictive reservoir simulation model was developed based on seismic attributes obtained from the base 3D seismic survey and available well data. This simulation predicted that the CO{sub 2} injected into the reef would remain in the northern portion of the field. Two new wells, the State Charlton 4-30 and the Larsen 3-31, were drilled into the field in 2006 and 2008 respectively and supported this assessment. A second (or 'Monitor') 3D seismic survey was acquired during September 2007 over most of the field and duplicated the first (Base) survey, as much as possible. However, as the simulation and new well data available at that time indicated that the CO{sub 2} was concentrated in the northern portion of the field, the second seismic survey was not acquired over the extreme southern end of the area covered by the original (or Base) 3D survey. Basic processing was performed on the second 3D seismic survey and, finally, 4D processing methods were applied to both the Base and the Monitor surveys. In addition to this 3D data, a shear wave seismic data set was obtained at the same time. Interpretation of the 4D seismic data indicated that a significant amplitude change, not attributable to differences in acquisition or processing, existed at the locations within the reef predicted by the reservoir simulation. The reservoir simulation was based on the porosity distribution obtained from seismic attributes from the Base 3D survey. Using this validated reservoir simulation the location of oil within the reef at the time the Monitor survey was obtained and recommendations made for the drilling of additional EOR wells. The economic impact of this project has been estimated in terms of both enhanced oil recovery and CO{sub 2} sequestration potential. In the northern Michigan Basin alone, the Niagaran reef play is comprised of over 700 Niagaran reefs with reservoirs already depleted by primary production. Potentially there is over 1 billion bbls of oil (original oil in place minus primary recovery) remains in the reefs in Michigan, much of which could be more efficiently mobilized utilizing techniques similar to those employed in this study.

Brian Toelle

2008-11-30T23:59:59.000Z

187

All-metal valve structure for gas systems  

DOE Patents (OSTI)

A valve assembly with a resilient metal seat member is disclosed for providing a gas-tight seal in a gas handling system. The valve assembly also includes a valve element for sealing against the valve seat member; and an actuating means for operating the valve element. The valve seat member is a one-piece stainless steel ring having a central valve port and peripheral mounting flange, and an annular corrugation in between. A groove between the first and second ridges serves as a flexure zone during operation of the valve member and thus provides the seating pressure between the inner ridge or valve seat and the valve element. The outer annular ridge has a diameter less than said valve element to limit the seating motion of the valve element, preventing non-elastic deformation of the seat member.

Baker, R.W.; Pawlak, D.A.; Ramey, A.J.

1982-06-10T23:59:59.000Z

188

Hydraulic engine valve actuation system including independent feedback control  

DOE Patents (OSTI)

A hydraulic valve actuation assembly may include a housing, a piston, a supply control valve, a closing control valve, and an opening control valve. The housing may define a first fluid chamber, a second fluid chamber, and a third fluid chamber. The piston may be axially secured to an engine valve and located within the first, second and third fluid chambers. The supply control valve may control a hydraulic fluid supply to the piston. The closing control valve may be located between the supply control valve and the second fluid chamber and may control fluid flow from the second fluid chamber to the supply control valve. The opening control valve may be located between the supply control valve and the second fluid chamber and may control fluid flow from the supply control valve to the second fluid chamber.

Marriott, Craig D

2013-06-04T23:59:59.000Z

189

Application of Time-Lapse Seismic Monitoring for the Control and Optimization of CO2 Enhanced Oil Recovery Operations  

SciTech Connect

The ''Application of Time-Lapse Seismic Monitoring for the Control and Optimization of CO{sub 2} Enhanced Oil Recovery Operations'' project is investigating the potential for monitoring CO{sub 2} floods in carbonate reservoirs through the use of standard p-wave seismic data. This project will involve the use of 4D seismic (time lapse seismic) to try to observe the movement of the injected CO{sub 2} through the reservoir. The differences between certain seismic attributes, such as amplitude, will be used to detect and map the movement of CO{sub 2} within the reservoir. This technique has recently been shown to be effective in CO{sub 2} monitoring in EOR projects such as Weyborne. The project is being conducted in the Charlton 30/31 field in northern Michigan Basin which is a Silurian pinnacle reef that has completed its primary production. This field is now undergoing enhanced oil recovery using CO{sub 2}. The CO{sub 2} flood was initiated the end of 2005 when the injection of small amounts of CO{sub 2} begin in the A1 Carbonate. This injection was conducted for 2 months before being temporarily halted in order for pressure measurements to be conducted. The determination of the reservoir's porosity distribution is proving to be a significant portion of this project. In order to relate the differences observed between the seismic attributes seen on the multiple surveys and the actual location of the CO{sub 2}, a predictive reservoir simulation model had to be developed. From this model, an accurate determination of porosity within the carbonate reservoir must be obtained. For this certain seismic attributes have been investigated. The study reservoirs in the Charlton 30/31 field range from 50 to 400 acres in size. The relatively small area to image makes 3-D seismic data acquisition reasonably cost effective. Permeability and porosity vary considerably throughout the reef, thus it is essential to perform significant reservoir characterization and modeling prior to implementing a CO{sub 2} flood to maximize recovery efficiency. Should this project prove successful, the same technique could be applied across a large spectrum of the industry. In Michigan alone, the Niagaran reef play is comprised of over 700 Niagaran reefs with reservoirs already depleted by primary production. These reservoirs range in thickness from 200 to 400 ft and are at depths of 2000 to 5000 ft. Approximately 113 of these Niagaran oil fields have produced over 1 million bbls each and the total cumulative production is in excess of 300 million bbls and 1.4 Tcf. There could potentially be over 1 billion bbls of oil remaining in reefs in Michigan much of which could be mobilized utilizing techniques similar to those employed in this study.

Brian E. Toelle

2006-02-28T23:59:59.000Z

190

ISOLOK VALVE ACCEPTANCE TESTING FOR DWPF SME SAMPLING PROCESS  

Science Conference Proceedings (OSTI)

Evaluation of the Defense Waste Processing Facility (DWPF) Chemical Process Cell (CPC) cycle time identified several opportunities to improve the CPC processing time. Of the opportunities, a focus area related to optimizing the equipment and efficiency of the sample turnaround time for DWPF Analytical Laboratory was identified. The Mechanical Systems & Custom Equipment Development (MS&CED) Section of the Savannah River National Laboratory (SRNL) evaluated the possibility of using an Isolok{reg_sign} sampling valve as an alternative to the Hydragard{reg_sign} valve for taking process samples. Previous viability testing was conducted with favorable results using the Isolok sampler and reported in SRNL-STI-2010-00749 (1). This task has the potential to improve operability, reduce maintenance time and decrease CPC cycle time. This report summarizes the results from acceptance testing which was requested in Task Technical Request (TTR) HLW-DWPF-TTR-2010-0036 (2) and which was conducted as outlined in Task Technical and Quality Assurance Plan (TTQAP) SRNL-RP-2011-00145 (3). The Isolok to be tested is the same model which was tested, qualified, and installed in the Sludge Receipt Adjustment Tank (SRAT) sample system. RW-0333P QA requirements apply to this task. This task was to qualify the Isolok sampler for use in the DWPF Slurry Mix Evaporator (SME) sampling process. The Hydragard, which is the current baseline sampling method, was used for comparison to the Isolok sampling data. The Isolok sampler is an air powered grab sampler used to 'pull' a sample volume from a process line. The operation of the sampler is shown in Figure 1. The image on the left shows the Isolok's spool extended into the process line and the image on the right shows the sampler retracted and then dispensing the liquid into the sampling container. To determine tank homogeneity, a Coliwasa sampler was used to grab samples at a high and low location within the mixing tank. Data from the two locations were compared to determine if the contents of the tank were well mixed. The Coliwasa sampler is a tube with a stopper at the bottom and is designed to obtain grab samples from specific locations within the drum contents. A position paper (4) was issued to address the prototypic flow loop issues and simulant selections. A statistically designed plan (5) was issued to address the total number of samples each sampler needed to pull, to provide the random order in which samples were pulled and to group samples for elemental analysis. The TTR required that the Isolok sampler perform as well as the Hydragard sampler during these tests to ensure the acceptability of the Isolok sampler for use in the DWPF sampling cells. Procedure No.L9.4-5015 was used to document the sample parameters and process steps. Completed procedures are located in R&D Engineering job folder 23269.

Edwards, T.; Hera, K.; Coleman, C.; Jones, M.; Wiedenman, B.

2011-12-05T23:59:59.000Z

191

A novel fractional order fuzzy PID controller and its optimal time domain tuning based on integral performance indices  

Science Conference Proceedings (OSTI)

A novel fractional order (FO) fuzzy Proportional-Integral-Derivative (PID) controller has been proposed in this paper which works on the closed loop error and its fractional derivative as the input and has a fractional integrator in its output. The fractional ... Keywords: FLC tuning, Fractional order controller, Fuzzy PID, Genetic algorithm, Integral performance indices, Optimal PID tuning

Saptarshi Das; Indranil Pan; Shantanu Das; Amitava Gupta

2012-03-01T23:59:59.000Z

192

Real-time optimization of wind farms and fixed-head pumped-storage hydro-plants  

Science Conference Proceedings (OSTI)

Renewable energies and, in particular, wind power have come to the forefront in the electricity market in recent years. The main drawback of wind power generation, however, is the major difficulty in forecasting its production. For this reason, when ... Keywords: optimal control, pumped storage plant, wind farm

L. Bayón, J. M. Grau, M. M. Ruiz, P. M. Suárez

2013-10-01T23:59:59.000Z

193

Method and apparatus for monitoring motor operated valve motor ...  

A method and apparatus are provided for monitoring a motor operated valve during the brief period when the valve seats and the torque switch trips to deenergize the ...

194

A Method to Determine the Optimal Tank Size for a Chilled Water Storage System Under a Time-of-Use Electricity Rate Structure  

E-Print Network (OSTI)

In the downtown area of Austin, it is planned to build a new naturally stratified chilled water storage tank and share it among four separated chilled water plants. An underground piping system is to be established to connect these four plants together. This paper presents the method of determining the optimal tank size as well as corresponding optimal operating strategies for this project. Based on the analysis of the historical log data, utility rate structures, and equipment information, the baseline profiles of electricity fed to buildings, plant cooling load, and utility billing cost for each plant are generated. A simplified TES plus four plants model is built based on some assumptions. The results show that a 3.5 million gallon tank has the shortest payback time and the projected total capital cost is within the budget. The annual billing cost savings are $907,231 and the simple payback time is 12.5 years.

Zhang, Z.; Turner, W. D.; Chen, Q.; Xu, C.; Deng, S.

2010-01-01T23:59:59.000Z

195

High precision high flow range control valve  

DOE Patents (OSTI)

A fluid control valve is described having a valve housing having first and second valve housing openings for the ingress and egress of fluid through the control valve. Disposed within a void formed by the control valve is a sleeve having at least one sleeve opening to permit the flow of fluid therethrough. A flow restricter travels within the sleeve to progressively block off the sleeve opening and thereby control flow. A fluid passageway is formed between the first valve housing opening and the outer surface of the sleeve. A second fluid passageway is formed between the inside of the sleeve and the second valve housing opening. Neither fluid passageway contains more than one 90.degree. turn. In the preferred embodiment only one of the two fluid passageways contains a 90.degree. turn. In another embodiment, the control valve housing is bifurcated by a control surface having control surface opening disposed therethrough. A flow restricter is in slidable contact with the control surface to restrict flow of fluid through the control surface openings.

McCray, John A. (Idaho Falls, ID)

1999-01-01T23:59:59.000Z

196

Vertical pump with free floating check valve  

DOE Patents (OSTI)

A vertical pump with a bottom discharge having a free floating check valve isposed in the outlet plenum thereof. The free floating check valve comprises a spherical member with a hemispherical cage-like member attached thereto which is capable of allowing forward or reverse flow under appropriate conditions while preventing reverse flow under inappropriate conditions.

Lindsay, Malcolm (O' Hara Township, Allegheny County, PA)

1980-01-01T23:59:59.000Z

197

Low energy ion beam assisted deposition of a spin valve  

Science Conference Proceedings (OSTI)

The spin dependent electron transport in giant magnetoresistive (GMR) multilayers is significantly affected by the atomic scale structure of their interfaces. Devices with atomically flat and chemically sharp interfaces are preferred for magnetic sensor and memory applications. Recent atomic simulations of the atom-by-atom assembly of these devices indicate that near optimal interfacial structures can be created using low energy, ion assisted vapor deposition techniques with ion energies in the 5-10 eV range. A recently developed biased target ion beam deposition system has been used to experimentally test this hypothesis. Prototypical Ta/NiFe/Co/Cu/Co/FeMn/Cu spin valve structures were first grown using (simultaneous) argon ion assistance during deposition of the Co/Cu/Co trilayer part of the spin valve multilayer. Assisting ion energies of around 10 eV resulted in structures with a 30% higher magnetoresistance ratio and significantly reduced coupling field compared to samples grown with no ion assistance or with ion energies above 15 eV. These results are consistent with the atomistic simulation predictions. Other promising ion assistance schemes identified by the simulations were then used to deposit the Ta, NiFe, FeMn, and the top copper layer. A near optimal strategy was identified that resulted in the further improvement of the GMR ratio.

Quan, J. J.; Wolf, S. A.; Wadley, H. N. G. [Department of Materials Science and Engineering, School of Engineering and Applied Science, University of Virginia, Charlottesville, Virginia 22903 (United States)

2007-04-01T23:59:59.000Z

198

Valve for controlling solids flow  

DOE Patents (OSTI)

A valve for controlling the flow of solids comprises a vessel having an overflow point, an inlet line for discharging solids into the vessel positioned within the vessel such that the inlet line's discharge point is lower than the vessel's overflow point, and apparatus for introducing a fluidizing fluid into the vessel. The fluidizing fluid fluidizes the solids within the vessel so that they overflow at the vessel's overflow point. For the removal of nuclear waste product the vessel may be placed within a sealed container having a bottom connected transport line for transporting the solids to storage or other sites. The rate of solids flow is controlled by the flow rate of the fluidizing fluid and by V-notch weirs of different sizes spaced about the top of the vessel.

Staiger, M. Daniel (Idaho Falls, ID)

1985-01-01T23:59:59.000Z

199

A novel approach for estimation of optimal embedding parameters of nonlinear time series by structural learning of neural network  

Science Conference Proceedings (OSTI)

In this work a novel approach for estimation of embedding parameters for reconstruction of underlying dynamical system from the observed nonlinear time series by a feedforward neural network with structural learning is proposed. The proposed scheme of ... Keywords: Chaos, Embedding parameters, Embedding theorem, Neural network, Nonlinear time series, Strange attractor, Structural learning

Yusuke Manabe; Basabi Chakraborty

2007-03-01T23:59:59.000Z

200

Method and apparatus for monitoring motor operated valve motor output torque and power at valve seating  

DOE Patents (OSTI)

A method and apparatus are provided for monitoring a motor operated valve during the brief period when the valve seats and the torque switch trips to deenergize the valve motor. The method uses voltage measurements on the load side of a deenergizing switch that opens to deenergize the motor to determine, among other things, final motor rotational speed and the decelerating torque at motor deenergization.

Casada, Donald A. (Oak Ridge, TN)

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Method and apparatus for monitoring motor operated valve motor output torque and power at valve seating  

DOE Patents (OSTI)

A method and apparatus are provided for monitoring a motor operated valve during the brief period when the valve seats and the torque switch trips to deenergize the valve motor. The method uses voltage measurements on the load side of a deenergizing switch that opens to deenergize the motor to determine, among other things, final motor rotational speed and the decelerating torque at motor deenergization. 14 figs.

Casada, D.A.

1996-01-16T23:59:59.000Z

202

Engineering Technical Training Modules - Throttle Valves 1.0  

Science Conference Proceedings (OSTI)

The purpose of this training module is to provide an understanding of specifying throttle valves in a nuclear power plant. The module provides the student with an understanding of the different types of throttle valves, how to select a throttle valve, understand the flow characteristics of different throttle valves, and understanding negative characteristics that can occur when the wrong valve is chosen for different applications. Prior to using this module, the student should understand the fundamental...

2011-06-29T23:59:59.000Z

203

EPRI-Marshall Electric Motor-Operated Valve (Block Valve) Interim Test Data Report  

Science Conference Proceedings (OSTI)

At the request of participating PWR utilities, an overall program was developed at EPRI for the full-scale testing of a representative set of primary-system safety and relief valves. The program was to assist the PWR utilities in meeting NUREG 0737, Item II.D.1.A requirements. Although not a formal part of the program, some block valve operability data were also obtained during the relief valve testing performed at Marshall Steam Station in Terrell, North Carolina. A total of seven block valve designs we...

1982-07-01T23:59:59.000Z

204

Valve studies: Hydrogen fluoride monitoring of UF{sub 6} cylinder valves  

Science Conference Proceedings (OSTI)

Uranium hexafluoride (UF{sub 6}) cylinder valves have, like the cylinders, been in use and/or storage for periods ranging from 15 to 44 years. Visual inspection of the cylinders has shown that the extent of corrosion and the overall cylinder condition varies widely throughout the storage yards. One area of concern is the integrity of the cylinder valves. Visual inspection has found deposits which have been identified as radioactive material on or near the valves. These deposits suggest leakage of UF{sub 6} and may indicate valve degradation; however, these deposits may simply be residual material from cylinder filling operations.

Leedy, R.R.; Ellis, A.R.; Hoffmann, D.P.; Marsh, G.C. [and others

1996-08-01T23:59:59.000Z

205

Method for valve seating control for an electro-hydraulic engine valve  

DOE Patents (OSTI)

Valve lift in an internal combustion engine is controlled by an electro-hydraulic actuation mechanism including a selectively actuable hydraulic feedback circuit.

Sun, Zongxuan (Plymouth, MN)

2011-01-11T23:59:59.000Z

206

Frostless heat pump having thermal expansion valves  

DOE Patents (OSTI)

A heat pump system having an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant and further having a compressor, an interior heat exchanger, an exterior heat exchanger, a heat pump reversing valve, an accumulator, a thermal expansion valve having a remote sensing bulb disposed in heat transferable contact with the refrigerant piping section between said accumulator and said reversing valve, an outdoor temperature sensor, and a first means for heating said remote sensing bulb in response to said outdoor temperature sensor thereby opening said thermal expansion valve to raise suction pressure in order to mitigate defrosting of said exterior heat exchanger wherein said heat pump continues to operate in a heating mode.

Chen, Fang C [Knoxville, TN; Mei, Viung C [Oak Ridge, TN

2002-10-22T23:59:59.000Z

207

Install Removable Insulation on Valves and Fittings  

Science Conference Proceedings (OSTI)

This revised ITP tip sheet on installing removable insulation on valves and fittings provides how-to advice for improving the system using low-cost, proven practices and technologies.

Not Available

2006-01-01T23:59:59.000Z

208

Design of a Real-Time Adaptive Power Optimal Sensor System Ari Y. Benbasat and Joseph A. Paradiso  

E-Print Network (OSTI)

sensors, their sampling rate and accuracy, and algorithms to describe both the state transitions and any state because one cycle is necessary to confirm the transition. Table 1: Summary of states and power usage (µC: MSP430F147, Gyro: ADXRS300, Accel: ADXL202) State % of Time Sensors Rate Sensor Power

209

Optimization Online  

E-Print Network (OSTI)

NEOS Optimization Server · NEOS Optimization Guide · Linear Programming FAQ · Nonlinear Programming FAQ · Mathematical Programming Glossary ...

210

Valve Application, Maintenance, and Repair Guide: In Situ State-of-the-Art Valve Welding Repair (Gate, Globe, & Check Valves), Volum e 2  

Science Conference Proceedings (OSTI)

The Valve Application, Maintenance and Repair Guide is a three volume series that provides a generic overview of valve application selection, maintenance, and repair. Volume 2 of this series is a comprehensive guide for in situ weld repair of gate, globe, and check valve components such as bodies, bonnets, discs, and seats. The information in this guide, though directed toward nuclear plant personnel, will assist all power plant engineers, planners, and maintenance personnel responsible for valve mainten...

1996-12-31T23:59:59.000Z

211

Diffusion bonding resistant valve development for sodium service  

SciTech Connect

Unanticipated functional failures occurred in valves undergoing containment integrity testing for liquid sodium service. The failures resulted from diffusion bonding of the Stellite 6B valve plug to the Type 316 stainless steel (SS) seat. As a result of these failures, a valve development program was undertaken. A modified valve incorporating a Tribaloy 800 plug showed significant improvement in resistance to diffusion bonding but still failed after long term exposure in a closed position. A second modified valve using Tribaloy 800 in both the valve plug and seat successfully resisted diffusion bonding failure. This paper reports the details of the testing and posttest valve examinations. The results of scanning electron microscopy, dispersive x-ray spectrometry, and metallography provide the characteristics of the valve failures. Limitations of the various valve designs are also discussed.

Crandall, D.L.; Low, J.O.; Chung, D.T.; Loop, R.B.

1984-04-16T23:59:59.000Z

212

A WEAR MODEL FOR DIESEL ENGINE EXHAUST VALVES  

DOE Green Energy (OSTI)

The work summarized here comprises the concluding effort of a multi-year project, funded by the U.S. Department of Energy, Office of Vehicle Technologies. It supports the development of a better understanding of advanced diesel engine designs in which enhanced power density, energy efficiency, and emissions control place increasing demands upon the durability of engine materials. Many kinds of metallic alloys are used in engines depending on the operating stresses, temperatures, and chemical environments. Exhaust valves, for example, are subjected to high temperatures and repetitive surface contacts that place demands on durability and frictional characteristics of the materials. Valves must continue to seal the combustion chamber properly for thousands of hours of cyclic engine operation and under varying operating conditions. It was the focus of this effort to understand the wear processes in the valve-seat area and to develop a model for the surface deformation and wear of that important interface. An annotated bibliography is provided to illustrate efforts to understand valve wear and to investigate the factors of engine operation that affect its severity and physical manifestation. The project for which this modeling effort was the final task, involved construction of a high-temperature repetitive impact test system as well as basic tribology studies of the combined processes of mechanical wear plus oxidation at elevated temperatures. Several publications resulted from this work, and are cited in this report. The materials selected for the experimental work were high-performance alloys based on nickel and cobalt. In some cases, engine-tested exhaust valves were made available for wear analysis and to ensure that the modes of surface damage produced in experiments were simulative of service. New, production-grade exhaust valves were also used to prepare test specimens for experimental work along with the other alloy samples. Wear analysis of valves and seats run for hundreds of hours in heavy-duty diesels provided insights into the kinds of complexity that the contact conditions in engines can produce, and suggested the physical basis for the current approach to modeling. The model presented here involves four terms, two representing the valve response and two for its mating seat material. The model's structure assumes that wear that takes place under a complex combination of plastic deformation, tangential shear, and oxidation. Tribolayers form, are removed, and may reform. Layer formation affects the friction forces in the interface, and in turn, the energy available to do work on the materials to cause wear. To provide friction data for the model at various temperatures, sliding contact experiments were conducted from 22 to 850 C in a pin-on-disk apparatus at ORNL. In order to account for the behavior of different materials and engine designs, parameters in all four terms of the model can be adjusted to account for wear-in and incubation periods before the dominant wear processes evolve to their steady-state rates. For example, the deformation rate is assumed to be maximum during the early stages of operation, and then, due to material work-hardening and the increase in nominal contact area (which reduces the load per unit area), decreases to a lower rate at long times. Conversely, the rate of abrasion increases with time or number of cycles due to the build-up of oxides and tribo-layers between contact surfaces. The competition between deformation and abrasion results in complex, non-linear behavior of material loss per cycle of operation. Furthermore, these factors are affected by valve design features, such as the angle of incline of the valve seat. Several modeling scenarios are presented to demonstrate how the wear profile versus number of cycles changes in response to: (a) different relative abrasion rates of the seat and valve materials, (b) the friction coefficient as a function of temperature, (c) the relative deformation contribution of valve and seat materials, and (d) an interruption in the dominant we

Blau, Peter Julian [ORNL

2009-11-01T23:59:59.000Z

213

Subsea production test valve assembly  

SciTech Connect

In the subsea test assembly securable within a blowout preventer stack above a subterranean well and positionable between upper and lower portions of a tubular conduit in fluid communication with a production zone within the well, the test assembly is described including an upper subassembly carriable with the upper conduit portion, a lower subassembly carriable with the lower conduit portion, and valve means in the lower subassembly manipulatable between opened and closed positions to control fluid flow within the conduit. The improvement comprises: the upper subassembly including an upper housing and first rigid dog means fixedly secured to the upper housing; the lower subassembly including a lower housing and second rigid dog means fixedly secured to the lower housing; the first rigid dog means positionable between a latch position for latching the upper and lower subassemblies and an unlatch position for unlatching the upper and lower subassemblies upon rotational movement of the first dog means with respect to the second dog means; and lock means axially movable relative to the first and second dog means from a lock position for limiting rotational movement of the first dog means with respect to the second dog means to an unlock position for allowing the first dog means to rotate relative to the second dog means and unlatch the upper subassembly from the lower subassembly.

Yates, P.D.

1988-03-22T23:59:59.000Z

214

Simulant Development for Hanford Tank Farms Double Valve Isolation (DVI) Valves Testing  

SciTech Connect

Leakage testing of a representative sample of the safety-significant isolation valves for Double Valve Isolation (DVI) in an environment that simulates the abrasive characteristics of the Hanford Tank Farms Waste Transfer System during waste feed delivery to the Waste Treatment and Immobilization Plant (WTP) is to be conducted. The testing will consist of periodic leak performed on the DVI valves after prescribed numbers of valve cycles (open and close) in a simulated environment representative of the abrasive properties of the waste and the Waste Transfer System. The valve operations include exposure to cycling conditions that include gravity drain and flush operation following slurry transfer. The simulant test will establish the performance characteristics and verify compliance with the Documented Safety Analysis. Proper simulant development is essential to ensure that the critical process streams characteristics are represented, National Research Council report “Advice on the Department of Energy's Cleanup Technology Roadmap: Gaps and Bridges”

Wells, Beric E.

2012-12-21T23:59:59.000Z

215

Fault-Tolerant Average Execution Time Optimization for General-Purpose Multi-Processor System-On-Chips, Design  

E-Print Network (OSTI)

Abstract 1 Fault-tolerance is due to the semiconductor technology development important, not only for safety-critical systems but also for general-purpose (non-safety critical) systems. However, instead of guaranteeing that deadlines always are met, it is for general-purpose systems important to minimize the average execution time (AET) while ensuring fault-tolerance. For a given job and a soft (transient) error probability, we define mathematical formulas for AET that includes bus communication overhead for both voting (active replication) and rollback-recovery with checkpointing (RRC). And, for a given multi-processor system-on-chip (MPSoC), we define integer linear programming (ILP) models that minimize AET including bus communication overhead when: (1) selecting the number of checkpoints when using RRC, (2) finding the number of processors and job-to-processor assignment when using voting, and (3) defining fault-tolerance scheme (voting or RRC) per job and defining its usage for each job. Experiments demonstrate significant savings in AET. I.

Mikael Väyrynen; Virendra Singh; Erik Larsson

2011-01-01T23:59:59.000Z

216

Time-Temperature-Transformation Study of Simulated Hanford Tank Waste (AZ-101) and Optimization of Glass Formulation for Processing Such Waste  

SciTech Connect

This paper presents the current results of a study for the optimization of the quality of the wasteform to be produced by vitrification of Hanford High Level Waste (HLW). A simulant of the content of Hanford Tank AZ-101 has been used for the experiments. A first phase of the research focused on the wasteform composition and showed that a high quality and chemical-resistant wasteform can be formed incorporating 60 weight % of dried waste into a borosilicate glass enriched with zinc oxide and boric acid and provided some indication about the heat treatment of the melt. A second phase of the study, still in progress, refines these findings. A detailed crystallinity survey of the waste form after various heat treatments has been performed, culminating in the development of a time-temperature-transformation (TTT) diagram. The results of the first phase of research and preliminary results from the second phase are described.

Ramsey, W. G.; Kauffman, B. M.; Bricka, M.; Meaker, T. F.; Giordana, A.; Smith, J. D.; Miller, F. S.; Bohannan, E.; Powell, J.; Reich, M.; Jordan, J.; Venter, L.; Barletta, R. E.; Ramsey, A. A.; Maise, G. M.; Manowitz, B.; Steinberg, M.; Salzano, F.

2003-02-26T23:59:59.000Z

217

Design of a Thermally-Actuated Gas Lift Safety Valve  

E-Print Network (OSTI)

Gas-lifted oil wells are susceptible to failure through malfunction of gas lift valve assemblies (GLV). One failure mode occurs when the GLV check valve fails and product passes into the well annulus, potentially reaching ...

Gilbertson, Eric W.

218

Miniature Fluid Control Valve - Oak Ridge National Laboratory  

Summary: Technology Description A very small control valve that is used to control flow into and out of a finger prosthesis. The valve makes use of a spring loaded poppet

219

Improve safety with pilot operated relief valves  

Science Conference Proceedings (OSTI)

A weakness inherent in balanced bellows pressure relief valves (PRVs) that can cause premature failure can be avoided by using pilot operated PRVs as an alternative. Now better able to handle adverse service conditions, pilot operated PRVs are suitable for a wide range of gas, liquid and mixed-phase services. Traditionally, however, balanced bellows PRVs have been applied as overpressure protection for three notable reasons: a constant PRV set pressure with the presence of variable, superimposed back pressure (at the PRV outlet prior to its opening); valve stability and adequate capacity when built-up back pressure (at the PRV outlet during its relief cycle) exceeds 10%; and spring and guided parts barriered from the process fluid. With these benefits in mind, balanced bellows PRVs have been generally adapted by many hydrocarbon processing companies that have experienced costly, and often dangerous, premature bellows failures. Corrosion, valve instability and/or bellows flutter are causes of these failures.

Emerson, G. [Anderson, Greenwood and Co., Stafford, TX (United States)

1996-10-01T23:59:59.000Z

220

Exhaust gas bypass valve control for thermoelectric generator  

DOE Patents (OSTI)

A method of controlling engine exhaust flow through at least one of an exhaust bypass and a thermoelectric device via a bypass valve is provided. The method includes: determining a mass flow of exhaust exiting an engine; determining a desired exhaust pressure based on the mass flow of exhaust; comparing the desired exhaust pressure to a determined exhaust pressure; and determining a bypass valve control value based on the comparing, wherein the bypass valve control value is used to control the bypass valve.

Reynolds, Michael G; Yang, Jihui; Meisner, Greogry P.; Stabler, Francis R.; De Bock, Hendrik Pieter (Peter) Jacobus; Anderson, Todd Alan

2012-09-04T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Worcester Solenoid Actuated Gas Operated MCO Isolation Valves  

SciTech Connect

These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as Integral parts of the actuator that are used in different process streams within the CVDF hood. The valves fail closed (on loss of pressure or electrical) for MCO isolation to either reduce air in leakage or loss of He. All valves have coupling for transverse actuator mounting.

VAN KATWIJK, C.

2000-06-06T23:59:59.000Z

222

Worchester Solenoid Actuated Gas Operated MCO Isolation Valves  

Science Conference Proceedings (OSTI)

These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as integral parts of the actuator that are used in process streams within the CWF hood. The valves fail closed (on loss of pressure or electrical) to prevent MCO vent drain to either reduce air In-leakage or loss of He. The valves have couplings for transverse actuator mounting.

MISKA, C.R.

2000-11-13T23:59:59.000Z

223

Worcester Solenoid Actuated Gas Operated MCO Isolation Valves  

Science Conference Proceedings (OSTI)

These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as integral parts of the actuator that are used in different process streams within the CVDF hood. The valves fail closed (on loss of pressure or electrical) for MCO isolation to either reduce air leakage or loss of He. All valves have coupling for transverse actuator mounting.

MISKA, C.R.

2000-11-13T23:59:59.000Z

224

Worcester Solenoid Actuated Gas Operated MCO Isolation Valves  

Science Conference Proceedings (OSTI)

These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as integral parts of the actuator that are used in different process streams within the CVDF hood. The valves fail closed (on loss of pressure or electrical) for MCO isolation to either reduce air in leakage or loss of He. All valves have coupling for transverse actuator mounting.

MISKA, C.R.

2000-09-03T23:59:59.000Z

225

Worchester Solenoid Actuated Gas Operated MCO Isolation Valves  

SciTech Connect

These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as integral parts of the actuator that are used in process streams within the CVDF hood. The valves fail closed (on loss of pressure or electrical) to prevent MCO vent drain to either reduce air in-leakage or loss of He. The valves have couplings for transverse actuator mounting.

VAN KATWIJK, C.

2000-06-06T23:59:59.000Z

226

Scoping Study on the Safety Impact of Valve Spacing in Natural Gas Pipelines  

Science Conference Proceedings (OSTI)

The U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration (PHMSA) is responsible for ensuring the safe, reliable, and environmentally sound operation of the nation's natural gas and hazardous liquid pipelines. Regulations adopted by PHMSA for gas pipelines are provided in 49 CFR 192, and spacing requirements for valves in gas transmission pipelines are presented in 49 CFR 192.179. The present report describes the findings of a scoping study conducted by Oak Ridge National Laboratory (ORNL) to assist PHMSA in assessing the safety impact of system valve spacing. Calculations of the pressures, temperatures, and flow velocities during a set of representative pipe depressurization transients were carried out using a one-dimensional numerical model with either ideal gas or real gas properties for the fluid. With both ideal gas and real gas properties, the high-consequence area radius for any resulting fire as defined by Stevens in GRI-00/0189 was evaluated as one measure of the pipeline safety. In the real gas case, a model for convective heat transfer from the pipe wall is included to assess the potential for shut-off valve failures due to excessively low temperatures resulting from depressurization cooling of the pipe. A discussion is also provided of some additional factors by which system valve spacing could affect overall pipeline safety. The following conclusions can be drawn from this work: (1) Using an adaptation of the Stephens hazard radius criteria, valve spacing has a negligible influence on natural gas pipeline safety for the pipeline diameter, pressure range, and valve spacings considered in this study. (2) Over the first 30 s of the transient, pipeline pressure has a far greater effect on the hazard radius calculated with the Stephens criteria than any variations in the transient flow decay profile and the average discharge rate. (3) Other factors besides the Stephens criteria, such as the longer burn time for an accidental fire, greater period of danger to emergency personnel, increased unavoidable loss of gas, and possible depressurization cooling of the shut-off valves may also be important when deciding whether a change in the required valve spacing would be beneficial from a safety standpoint. (4) The average normalized discharge rate of {lambda}{sub avg} = 0.33 assumed by Stephens in developing his safety criteria is an excellent conservative value for natural gas discharge at the pressures, valve spacings, and pipe diameter used in this study. This conclusion remains valid even when real rather than ideal gas properties are considered in the analysis. (5) Significant pipe wall cooling effects (T{sub w} pipeline rupture accident.

Sulfredge, Charles David [ORNL

2007-07-01T23:59:59.000Z

227

Disc valve for sampling erosive process streams  

DOE Patents (OSTI)

This is a patent for a disc-type, four-port sampling valve for service with erosive high temperature process streams. Inserts and liners of ..cap alpha..-silicon carbide respectively, in the faceplates and in the sampling cavities, limit erosion while providing lubricity for a smooth and precise operation. 1 fig.

Mrochek, J.E.; Dinsmore, S.R.; Chandler, E.W.

1984-08-16T23:59:59.000Z

228

Separators for valve regulated lead acid batteries  

Science Conference Proceedings (OSTI)

This paper reviews some aspects of the past history of the valve regulated lead acid (VRLA) battery in relationship to microglass separators that have been used from the conception of VRLA technology. It also focuses on some aspects of compression properties of the separator.

Zguris, G.C. [Hollingsworth & Vose Co., West Groton, MT (United States)

1995-01-01T23:59:59.000Z

229

RECOVERY ACT: DYNAMIC ENERGY CONSUMPTION MANAGEMENT OF ROUTING TELECOM AND DATA CENTERS THROUGH REAL-TIME OPTIMAL CONTROL (RTOC): Final Scientific/Technical Report  

Science Conference Proceedings (OSTI)

This final scientific report documents the Industrial Technology Program (ITP) Stage 2 Concept Development effort on Data Center Energy Reduction and Management Through Real-Time Optimal Control (RTOC). Society is becoming increasingly dependent on information technology systems, driving exponential growth in demand for data center processing and an insatiable appetite for energy. David Raths noted, 'A 50,000-square-foot data center uses approximately 4 megawatts of power, or the equivalent of 57 barrels of oil a day1.' The problem has become so severe that in some cases, users are giving up raw performance for a better balance between performance and energy efficiency. Historically, power systems for data centers were crudely sized to meet maximum demand. Since many servers operate at 60%-90% of maximum power while only utilizing an average of 5% to 15% of their capability, there are huge inefficiencies in the consumption and delivery of power in these data centers. The goal of the 'Recovery Act: Decreasing Data Center Energy Use through Network and Infrastructure Control' is to develop a state of the art approach for autonomously and intelligently reducing and managing data center power through real-time optimal control. Advances in microelectronics and software are enabling the opportunity to realize significant data center power savings through the implementation of autonomous power management control algorithms. The first step to realizing these savings was addressed in this study through the successful creation of a flexible and scalable mathematical model (equation) for data center behavior and the formulation of an acceptable low technical risk market introduction strategy leveraging commercial hardware and software familiar to the data center market. Follow-on Stage 3 Concept Development efforts include predictive modeling and simulation of algorithm performance, prototype demonstrations with representative data center equipment to verify requisite performance and continued commercial partnering agreement formation to ensure uninterrupted development, and deployment of the real-time optimal control algorithm. As a software implementable technique for reducing power consumption, the RTOC has two very desirable traits supporting rapid prototyping and ultimately widespread dissemination. First, very little capital is required for implementation. No major infrastructure modifications are required and there is no need to purchase expensive capital equipment. Second, the RTOC can be rolled out incrementally. Therefore, the effectiveness can be proven without a large scale initial roll out. Through the use of the Impact Projections Model provided by the DOE, monetary savings in excess of $100M in 2020 and billions by 2040 are predicted. In terms of energy savings, the model predicts a primary energy displacement of 260 trillion BTUs (33 trillion kWh), or a 50% reduction in server power consumption. The model also predicts a corresponding reduction of pollutants such as SO2 and NOx in excess of 100,000 metric tonnes assuming the RTOC is fully deployed. While additional development and prototyping is required to validate these predictions, the relative low cost and ease of implementation compared to large capital projects makes it an ideal candidate for further investigation.

Ron Moon

2011-06-30T23:59:59.000Z

230

Statistical Performance Evaluation Of Soft Seat Pressure Relief Valves  

SciTech Connect

Risk-based inspection methods enable estimation of the probability of failure on demand for spring-operated pressure relief valves at the United States Department of Energy's Savannah River Site in Aiken, South Carolina. This paper presents a statistical performance evaluation of soft seat spring operated pressure relief valves. These pressure relief valves are typically smaller and of lower cost than hard seat (metal to metal) pressure relief valves and can provide substantial cost savings in fluid service applications (air, gas, liquid, and steam) providing that probability of failure on demand (the probability that the pressure relief valve fails to perform its intended safety function during a potentially dangerous over pressurization) is at least as good as that for hard seat valves. The research in this paper shows that the proportion of soft seat spring operated pressure relief valves failing is the same or less than that of hard seat valves, and that for failed valves, soft seat valves typically have failure ratios of proof test pressure to set pressure less than that of hard seat valves.

2013-03-26T23:59:59.000Z

231

Hydraulically actuated gas exchange valve assembly and engine using same  

DOE Patents (OSTI)

An engine comprises a housing that defines a hollow piston cavity that is separated from a gas passage by a valve seat. The housing further defines a biasing hydraulic cavity and a control hydraulic cavity. A gas valve member is also included in the engine and is movable relative to the valve seat between an open position at which the hollow piston cavity is open to the gas passage and a closed position in which the hollow piston cavity is blocked from the gas passage. The gas valve member includes a ring mounted on a valve piece and a retainer positioned between the ring and the valve piece. A closing hydraulic surface is included on the gas valve member and is exposed to liquid pressure in the biasing hydraulic cavity.

Carroll, Thomas S. (Peoria, IL); Taylor, Gregory O. (Hinsdale, IL)

2002-09-03T23:59:59.000Z

232

Technical evaluation: 300 Area steam line valve accident  

SciTech Connect

On June 7, 1993, a journeyman power operator (JPO) was severely burned and later died as a result of the failure of a 6-in. valve that occurred when he attempted to open main steam supply (MSS) valve MSS-25 in the U-3 valve pit. The pit is located northwest of Building 331 in the 300 Area of the Hanford Site. Figure 1-1 shows a layout of the 300 Area steam piping system including the U-3 steam valve pit. Figure 1-2 shows a cutaway view of the approximately 10- by 13- by 16-ft-high valve pit with its various steam valves and connecting piping. Valve MSS-25, an 8-in. valve, is located at the bottom of the pit. The failed 6-in. valve was located at the top of the pit where it branched from the upper portion of the 8-in. line at the 8- by 8- by 6-in. tee and was then ``blanked off`` with a blind flange. The purpose of this technical evaluation was to determine the cause of the accident that led to the failure of the 6-in. valve. The probable cause for the 6-in. valve failure was determined by visual, nondestructive, and destructive examination of the failed valve and by metallurgical analysis of the fractured region of the valve. The cause of the accident was ultimately identified by correlating the observed failure mode to the most probable physical phenomenon. Thermal-hydraulic analyses, component stress analyses, and tests were performed to verify that the probable physical phenomenon could be reasonably expected to produce the failure in the valve that was observed.

Not Available

1993-08-01T23:59:59.000Z

233

Subsurface safety valves: safety asset or safety liability  

SciTech Connect

This paper summarizes the methods used to compare the risk of a blowout for a well completed with a subsurface safety valve (SSSV) vs. a completion without an SSSV. These methods, which could be applied to any field, include a combination of SSSV reliability and conventional risk analyses. The Kuparuk River Unit Working Interest Owners recently formed a group to examine the risks associated with installing and maintaining SSSV's in the Kuparuk field. The group was charged with answering the question: ''Assuming Kuparuk field operating conditions, are SSSV's a safety asset, or do numerous operating and maintenance procedures make them a safety liability.'' The results indicate that for the Kuparuk River Unit, an SSSV becomes a safety liability when the mean time between SSSV failures is less than one year. Since current SSSV mean time to failure (MTTF) at Kuparuk is approximately 1000 days, they are considered a safety asset.

Busch, J.M.; Llewelyn, D.C.G.; Policky, B.J.

1983-10-01T23:59:59.000Z

234

Water cooling of HVDC thyristor valves  

SciTech Connect

It is generally accepted that water is a very effective medium to remove heat losses from any type of equipment. When used for HVDC thyristor valves, the fundamentals of electrolyte conduction and water chemistry need to be considered in the design of the cooling circuit. The characteristics of the materials used, in conjunction with high voltage stresses and circuit configuration, play an important role to assure longevity and corrosion-free performance.

Lips, H.P. (Siemens AG, Erlangen (Germany))

1994-10-01T23:59:59.000Z

235

The operation of LPG relief valves  

SciTech Connect

As stipulated by NFPA 58, all LPG storage containers must be equipped with one or more pressure relief devices. These devices are sized to prevent rupture of a normally charged container when exposed to fire. This paper describes in detail the functioning of the spring-loaded relief valve. The author discusses how the venting of LPGs can produce unacceptable risks and how training is a necessary part of controlling such a situation.

Stannard, J.H. Jr

1989-11-01T23:59:59.000Z

236

Method and system for measuring gate valve clearances and seating force  

DOE Patents (OSTI)

Valve clearances and seating force, as well as other valve operational parameters, are determined by measuring valve stem rotation during opening and closing operations of a translatable gate valve. The magnitude of the stem rotation, and the relative difference between the stem rotation on opening and closing provides valuable data on the valve internals in a non-intrusive manner.

Casada, Donald A. (Knoxville, TN); Haynes, Howard D. (Knoxville, TN); Moyers, John C. (Oak Ridge, TN); Stewart, Brian K. (Burns, TN)

1996-01-01T23:59:59.000Z

237

American Valve: Proposed Penalty (2010-CW-1411) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

American Valve: Proposed Penalty (2010-CW-1411) American Valve: Proposed Penalty (2010-CW-1411) American Valve: Proposed Penalty (2010-CW-1411) September 8, 2010 DOE alleged in a Notice of Proposed Civil Penalty that American Valve, Inc. failed to certify a variety of showerheads as compliant with the applicable water conservation standards. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have been tested and meet the applicable water conservation standards. This civil penalty notice advises the company of the potential penalties and DOE's administrative process, including the company's right to a hearing. American Valve: Proposed Penalty (2010-CW-1411) More Documents & Publications American Valve: Order (2010-CW-1411) Afeel: Proposed Penalty (2010-CW-07/1414)

238

16.323 Principles of Optimal Control, Spring 2006  

E-Print Network (OSTI)

Studies the principles of deterministic optimal control. Variational calculus and Pontryagin's maximum principle. Applications of the theory, including optimal feedback control, time-optimal control, and others. Dynamic ...

How, Jonathan P.

239

Predicted Effects of Tritium Exposures on Fast-Acting Piezoelectric Valves for Gas Fueling at TFTR  

SciTech Connect

The prospects for using piezoelectrically-driven valves with elastomeric or thermoplastic poppets in tritium gas service have been investigated. A modelling study of a typical valve incorporating ethylene-propylene rubber (EPR) or high density polyethylene (HDPE) was performed. Equations were developed linking applied voltage; ceramic bimorph preloading force, elastic deflection modulus, and specific deflection force (per volt applied); polymer elastic modulus, thickness, seal surface area, and compression (to make seal); elastomer compression set; thermoplastic creep modulus; and flow gap between seat and polymer tip. It was determined that, while EPR should seal the valve orifice more easily, HDPE should produce a valve flow rate vs. voltage curve less variant with time and exposure. Both should, however, be sealable and allow flow curves perturbed by less than or equal to 10% of full scale after ~100 days of exposure to 10{sup}5 Pa (1 atm) T{sub}2 gas (equivalent to ~7 x 10{sup}7 rad = 7 x 10{sup}5 Gy dosage).

Gill, J. T.; Pierce, C. W.

1985-04-01T23:59:59.000Z

240

U.S. Steam Turbine Valve Actuator Condition Assessment  

Science Conference Proceedings (OSTI)

This report provides nuclear and fossil plant personnel with current information on the inspection and assessment of steam turbine valve actuators.

2008-12-23T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

DEVELOPMENT OF FREEZE VALVE FOR USE IN THE MSRE  

SciTech Connect

Three types of frozen-seal valves'' were tested for possible use in the MSRE. The seal was melted by direct resistance heat, by induction heat, and by clamp-on Calrod heat. The frozen seal was made in a preformed restriction section of a standard piece of pipe by a cooling-gas jet stream directed at the restriction. All three valves performed satisfactorily through 100 test cycles. The Calrodheated valve was selected for MSRE use on the basis of simplicity of design and of operation. Two of the valves are successfully undergoing further tests on the MSRE Engineering Test Loop. (auth)

Richardson, M.

1962-02-28T23:59:59.000Z

242

American Valve: Order (2010-CW-1411) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Valve had failed to certify that certain showerhead models comply with the applicable water conservation standards. The Order adopted a Compromise Agreement, which reflected...

243

U.S. Steam Turbine Valve Metallurgy Guide  

Science Conference Proceedings (OSTI)

This report provides nuclear and fossil plant personnel with current information on the metallurgical aspects of the steam turbine valve components used in U.S. power plants.

2009-03-30T23:59:59.000Z

244

Computer Based Training: Check Valves 1.0  

Science Conference Proceedings (OSTI)

ETTM Check Valves is a computer based training module that allows users to access training when desired and review it at their own pace. It provides graphics and limited interactive features to enhance learning. The purpose of this module is to provide the user with a basis for selecting and sizing a check valve for nuclear station applications. While more than one valve type can be used for most applications, the intent is to point out the differences between check valve designs and to assist the user i...

2010-10-07T23:59:59.000Z

245

Meso-fluidic Control Valve - Oak Ridge National Laboratory  

Volume Systems Advantages: Small Size ... Meso-fluidic Control Valve-1974 Contact: Mark Reeves Oak Ridge National Laboratory P.O. Box 2008, Mail Stop ...

246

Optimal operation of pipeline systems using genetic algorithm  

Science Conference Proceedings (OSTI)

A Genetic Algorithm (GA) is used in this paper for the optimal operation, result in better solution than the existing one, of the pipeline systems under transient conditions caused by valve closure. Simulation of pipeline system is carried out here by ... Keywords: genetic algorithm, implicit method of characteristic, pipeline system, transient flow, water hammer

M. H. Afshar; M. Rohani

2009-05-01T23:59:59.000Z

247

Numerical Investigation of the Performance of Three Hinge Designs of Bileaflet Mechanical Heart Valves  

E-Print Network (OSTI)

parameters on bilea?et mechanical heart valve ?ow dynamics.J. Heart Valve Dis. 18:535–545, 2009. Gross, J. M. , M. C.two bilea?et mechanical heart valves under aortic and mitral

Simon, Hélène A.; Ge, Liang; Sotiropoulos, Fotis; Yoganathan, Ajit P.

2010-01-01T23:59:59.000Z

248

Stem control of a sliding-stem pneumatic control valve using a recurrent neural network  

Science Conference Proceedings (OSTI)

This paper presents a neural scheme for controlling an actuator of pneumatic control valve system. Bondgraph method has been used to model the actuator of control valve, in order to compare the response characteristics of valve. The proposed controller ...

Mohammad Heidari, Hadi Homaei

2013-01-01T23:59:59.000Z

249

EPRI/C-E PWR Safety Valve Test Report Volume 3: Test Results for Dresser Safety Valve Model 31739A  

Science Conference Proceedings (OSTI)

EPRI at the request of the PWR utilities developed an overall program for the testing of PWR primary system safety and relief valves. This program was in response to NUREG 0578 Item 2.1.2 and NUREG 0737 Item II.D.1.A requirements. This report documents the results of safety valve testing performed as part of the overall program at the EPRI/C-E Valve Test Facility located at Combustion Engineering's Kreisinger Development Laboratory, Windsor, Connecticut. Seven safety valves representative of those utiliz...

1983-02-01T23:59:59.000Z

250

Electric actuation of a surface controlled subsea safety valve  

E-Print Network (OSTI)

The growing technology associated with petroleum equipment has lead to an increase in electrical components used to measure, adjust and control many aspects of the petroleum extraction process. This increase in electrical use has lead to the conversion of many components from hydraulic operation to electric. Therefore, it is the purpose of this report to detail and propose an engineering solution to the electrical conversion of a surface controlled subsea safety valve (SCSSV). Preliminary analysis has resulted in the following important functional requirements that the SCSSV should operate within: Temperatures up to 350 F. Estimated operational life of 20 years. Peak available power of 4300 W (actual value will be much lower than this due to other power system drains). The three conceptual designs presented in this report are the following: Electric motor actuator with a solenoid latching detent. Linear actuation with a fluid reservoir locking valve. Rotational engagement with an electric locking clutch. After reviewing and comparing these concepts, the last concept was chosen to be further developed. This concept will have the least temperature sensitive components and fewer leak path problem areas. Upon completion of the detailed design phase an electric SCSSV solution has been proposed. The following is a brief list of the performance claims: Power requirement to open: 0.5 W. Time required to open valve: 10 minutes. Installable inline with 4-1/2 tubing. Operating temperature range: 20-350 F. H?S service certified. Hold open energy requirements 0~0.2 W. There are however practical issues that must be addressed to ensure reliable and satisfactory performance of the SCSSV. The actual efficiency of the cylindrical cam mechanism and reliability of the torque overload clutch must be empirically determined due to the number of theoretical assumptions used. Thus these items should be thoroughly tested in order to produce a reliable and satisfactory SCSSV. It is with these claims and working issue that this electrically converted SCSSV be fully developed and installed for electrical petroleum production systems.

Bartlett, Timothy Joseph

2002-01-01T23:59:59.000Z

251

Nuclear-radiation-actuated valve. [Patent application; for increasing coolant flow to blanket  

DOE Patents (OSTI)

The present invention relates to a breeder reactor blanket fuel assembly coolant system valve which increases coolant flow to the blanket fuel assembly to minimize long-term temperature increases caused by fission of fissile fuel created from fertile fuel through operation of the breeder reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

Christiansen, D.W.; Schively, D.P.

1982-01-19T23:59:59.000Z

252

Giant magnetoresistance in organic spin valves  

SciTech Connect

Interfacial diffusion between magnetic electrodes and organic spacer layers is a serious problem in the organic spintronics which complicates attempts to understand the spin-dependent transport mechanism and hurts the achievement of a desirably high magnetoresistance (MR). We deposit nanodots instead of atoms onto the organic layer using buffer layer assist growth. Spin valves using this method exhibit a sharper interface and a giant MR of up to {approx}300%. Analysis of the current-voltage characteristics indicates that the spin-dependent carrier injection correlates with the observed MR.

Sun, Da-Li [ORNL; Yin, Lifeng [ORNL; Sun, Chengjun [ORNL; Guo, Hangwen [ORNL; Gai, Zheng [ORNL; Zhang, Xiaoguang [ORNL; Ward, Thomas Z [ORNL; Cheng, Zhaohua [Chinese Academy of Sciences; Shen, Jian [ORNL

2010-01-01T23:59:59.000Z

253

Effect of reactor conditions on MSIV (main steam isolation valves)-ATWS power level  

SciTech Connect

In a boiling water reactor (BWR) when there is closure of the main steam isolation valves (MSIVs), the energy generated in the core will be transferred to the pressure suppression pool (PSP) via steam flows out of the relief valves. The pool has limited capacity as a heat sink and hence, if there is no reactor trip (an ATWS event), there is the possibility that the pool temperature may rise beyond acceptable limits. The present study was undertaken to determine how the initial reactor conditions affect the power during an MSIV-ATWS event. The time of interest is during the 20-30 minute period when it is assumed that the reactor is in a quasi-equilibrium condition with the water level and pressure fixed, natural circulation conditions and no control rod movement or significant boron in the core. The initial conditions of interest are the time during the cycle and the operating state. 4 refs., 2 tabs.

Diamond, D.J.

1987-01-01T23:59:59.000Z

254

Closed Loop Test Facility for hot dirty gas valves  

SciTech Connect

A design study of a closed loop test facility for eight-inch hot dirty gas valves is presented. The objective of the facility is to quality valves for use in coal gasifiers, combined cycle plants, and pressurized fluid bed combustors. Outline sketches and estimated costs are presented for the selected design.

Not Available

1980-02-06T23:59:59.000Z

255

Classification of prosthetic heart valve sounds: A parametric approach  

Science Conference Proceedings (OSTI)

People with heart problems have had their lives extended considerably with the development of the prosthetic heart valve. Great strides have been made in the development of the valves through the use of improved materials as well as efficient mechanical designs. However

J. V. Candy; H. E. Jones

1995-01-01T23:59:59.000Z

256

Cam-driven valve system for steam turbines  

SciTech Connect

This patent describes, in a steam turbine system including a source of motive steam and a turbine adapted to operate at less than a full load, the turbine including an improved cam-driven valve system for activating a varying number of steam control valves to permit transferring between a maximum arc-admission mode and a minimum arc-admission mode. It comprises: a steam chest for receiving the motive steam from the source, the steam chest including a plurality of valves connected to a corresponding turbine section and set for a minimum admission of motive steam into the turbine below 100 percent; a first cam lift means for actuating a portion of the valves and second cam lift means for actuating the remainder of the valves.

Silvestri, G.J. Jr.

1990-02-27T23:59:59.000Z

257

A characterization of check valve degradation and failure experience in the nuclear power industry: 1991 Failures, Volume 2  

SciTech Connect

Review and characterization of check valve failures taken from the Institute of Nuclear Power Operation`s Nuclear Plant Reliability Data System was performed in accordance with part two of a three-phase project sponsored by the US Nuclear Regulatory Commission. The analysis was performed for check valve failures occurring in 1991 and is intended to update the previous analysis performed for the time period 1984--1990. To maintain consistency and for ease of the 1991 analysis presents the same parameters and cross-correlations in essentially the same format as the 1984--1990 study. Additional data was obtained for the 1991 analysis, including information related to specific check valve type. This information is presented in a separate section of the report.

McElhaney, K.L. [Oak Ridge National Lab., TN (United States)

1995-07-01T23:59:59.000Z

258

Optimization Online - A well-posed shooting algorithm for optimal ...  

E-Print Network (OSTI)

Oct 17, 2011 ... Abstract: In this article we establish for the first time the well-posedness of the shooting algorithm applied to optimal control problems for which ...

259

Optimization Online - Coordinators  

E-Print Network (OSTI)

... Programming); William Hart — Sandia National Laboratory; (Combinatorial Optimization / Global Optimization / Optimization Software and Modeling Systems

260

Wireless Sensing, Monitoring and Optimization for Campus-Wide Steam Distribution  

Science Conference Proceedings (OSTI)

The US Congress has passed legislation dictating that all government agencies establish a plan and process for improving energy efficiencies at their sites. In response to this legislation, Oak Ridge National Laboratory (ORNL) has recently conducted a pilot study to explore the deployment of a wireless sensor system for a real-time measurement-based energy efficiency optimization. With particular focus on the 12-mile long steam distribution network in our campus, we propose an integrated system-level approach to optimize energy delivery within the steam distribution system. Our approach leverages an integrated wireless sensor and real-time monitoring capability. We make real time state assessment on the steam trap health and steam flow estimate of the distribution system by mounting acoustic sensors on the steam pipes/traps/valves and observing measurements of these sensors with state estimators for system health. Our assessments are based on a spectral-based energy signature scheme that interprets acoustic vibration sensor data to estimate steam flow rates and assess steam traps status. Experimental results show that the energy signature scheme has the potential to identify different steam trap states and it has sufficient sensitivity to estimate flow rate. Moreover, results indicate a nearly quadratic relationship over the test region between the overall energy signature factor and flow rate in the pipe. We are able to present the steam flow and steam trap status, sensor readings, and the assessed alerts as an interactive overlay within a web-based Google Earth geographic platform that enables decision makers to take remedial action. The goal is to achieve significant energy-saving in steam lines by monitoring and acting on leaking steam pipes/traps/valves. We believe our demonstration serves as an instantiation of a platform that extends implementation to include newer modalities to manage water flow, sewage and energy consumption.

Olama, Mohammed M [ORNL; Allgood, Glenn O [ORNL; Kuruganti, Phani Teja [ORNL; Sukumar, Sreenivas R [ORNL; Woodworth, Ken [ORNL; Lake, Joe E [ORNL

2011-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Engine valve and method of producing the same  

SciTech Connect

An engine valve of an internal combustion engine is described which consists of: a hollow tube member formed of a drawn steel tube, the hollow tube member having a central portion comprising a tubular body, and a first end part which is flared outwardly and includes an open end peripheral portion at the extreme end of the first end part, the hollow tube member tubular body constituting a valve stem section; a generally disc-shaped lid member made of metal and having a peripheral portion integrally connected with the open end peripheral portion of the hollow tube member, the lid member and the first end part of the hollow tube member constituting a valve head section; and a stem end member made of metal and integrally connected with a second part of the hollow tube member; a filler metal comprising stellite disposed in contact with the open end peripheral portion of the hollow tube member first end part and the peripheral portion of the disc-shaped lid member to secure together the hollow tube member and the lid member to thereby form the integral connection, the stellite filler metal being a wear and corrosion resistant nonferrous alloy, the filler metal being formed as a padding having a peripheral surface including a valve face for contacting a valve seat of an engine; and a filling comprising an aluminum alloy containing silicon, the filling being disposed in the valve head section to fill the valve head section.

Hayashi, Y.

1986-07-01T23:59:59.000Z

262

Analysis of a Third-Generation Princeton Tri-leaflet Mechanical Heart Valve  

E-Print Network (OSTI)

Analysis of a Third-Generation Princeton Tri-leaflet Mechanical Heart Valve Michael Hsu Advisor heart valve · Static analysis of leaflet under uniform pressure of 10 MPa Summer Objectives · Find Heart valve disease · Over 5 million affected · Over 225,000 valve- replacement surgeries performed

Petta, Jason

263

Control system for the turbomolecular pumping stations and sector valves of the CERN Intersecting Storage Rings  

E-Print Network (OSTI)

Control system for the turbomolecular pumping stations and sector valves of the CERN Intersecting Storage Rings

Gröbner, Oswald

1971-01-01T23:59:59.000Z

264

Noninvasive valve monitor using constant magnetic and/or DC electromagnetic field  

DOE Patents (OSTI)

One or more sources of steady magnetic field are carefully located on the outside of a valve body. The constant magnetic field is transmitted into the valve body and valve internals. A magnetic field detector carefully located on the outside of the valve body detects the intensity of the magnetic field at its location. As the position of a valve internal part is changed, there is an alteration in the magnetic field in the valve, and a consequent change in the detected magnetic field. Changes in the detected signal provide an indication of the position and motion of the valve internals.

Casada, D.A.; Haynes, H.D.

1993-08-17T23:59:59.000Z

265

Noninvasive valve monitor using constant magnetic and/or DC electromagnetic field  

SciTech Connect

One or more sources of steady magnetic field are carefully located on the outside of a valve body. The constant magnetic field is transmitted into the valve body and valve internals. A magnetic field detector carefully located on the outside of the valve body detects the intensity of the magnetic field at its location. As the position of a valve internal part is changed, there is an alteration in the magnetic field in the valve, and a consequent change in the detected magnetic field. Changes in the detected signal provide an indication of the position and motion of the valve internals.

Casada, Donald A. (Knoxville, TN); Haynes, Howard D. (Knoxville, TN)

1993-01-01T23:59:59.000Z

266

Optimization Online - Optimal Design of Electrical Machines ...  

E-Print Network (OSTI)

Jun 8, 2011 ... Optimal Design of Electrical Machines: Mathematical Programming ... Science and Engineering (Multidisciplinary Design Optimization ).

267

Computationally Optimized Homogenization Heat Treatment of ...  

usually entails numerous samples, substantial furnace time and associated energy, ... to optimize the homogenization process for efficiency and cost ...

268

Analog and digital control of an electronic throttle valve  

E-Print Network (OSTI)

Two electronic throttler controllers were designed and implemented for an automotive throttle valve on a four-cylinder, spark-ignition gasoline engine. The first controller was designed using operational amplifiers and ...

Martins, Tomás V

2012-01-01T23:59:59.000Z

269

Replace Pressure-Reducing Valves with Backpressure Turbogenerators  

SciTech Connect

This revised ITP steam tip sheet on replacing pressure-reducing valves provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

Not Available

2006-01-01T23:59:59.000Z

270

Technical Repair Guide for Rotork Valve Actuators "NA" Range Models  

Science Conference Proceedings (OSTI)

This guide provides comprehensive technical information on Rotork valve actuator operation, maintenance, testing, and troubleshooting. Its design provides the user with a uniform methodology to reduce human errors and increase actuator reliability.

1995-12-31T23:59:59.000Z

271

Efforts by the nuclear industry to evaluate check valve failures  

SciTech Connect

Recent studies identified approximately 4000 check valve failures that occurred from 1984-1991. Of these, approximately 1600 were determined to be significant enough to require further analysis. This is to be compared with the existing check valve population of nearly 21,000 valves. The strategy proposed in this paper is to establish a refined, centralized check valve failure/reliability database based in part on existing Institute of Nuclear Power Operations (INPO) Nuclear Plant Reliability Data System (NPRDS) data. Ideally the database would be maintained in a central location, augmented with specific component information, overall reliability information, and updated at least biannually. The data would be available to sort and search as desired. The conceptual plan is provided and possible uses of the database are given.

Hart, K.; McElhaney, K.L.; Casada, D.A.

1994-12-31T23:59:59.000Z

272

Failure Mode and Sensitivity Analysis of Gas Lift Valves  

E-Print Network (OSTI)

Gas-lifted oil wells are susceptible to failure through malfunction of gas lift valves. This is a growing concern as offshore wells are drilled thousands of meters below the ocean floor in extreme temperature and pressure ...

Gilbertson, Eric W.

273

Nonlinear springs with applications to flow regulation valves and mechanisms  

E-Print Network (OSTI)

This thesis focuses on the application of nonlinear springs for fluid flow control valves where geometric constraints, or fabrication technologies, limit the use of available solutions. Types of existing nonlinear springs ...

Freeman, David Calvin

2008-01-01T23:59:59.000Z

274

Design of an electronically-actuated gas lift safety valve  

E-Print Network (OSTI)

Gas lift valves are widely used in oil production fields to pump recycled gas and nitrogen into the production tubing, to sustain production by aerating the oil and lifting it to the ground or sea surface. Today's industry ...

Yu, Changkuan, S.M. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

275

Steam Turbine Casing and Valve Body Repair Guidelines  

Science Conference Proceedings (OSTI)

Today’s flexible mode of operation can result in damage to heavy-section components, such as steam turbine and valve casings. Thus, owners and operators are often faced with repairing a critical component. This report is part of a set of documents that address the key areas in the asset management of steam turbine casings and valve bodies—nondestructive evaluation and damage detection, repair, and life ...

2013-12-14T23:59:59.000Z

276

Worcester 1 Inch Solenoid Actuated Gas Operated SCHe System Valves  

SciTech Connect

1 inch gas-operated full-port ball valves incorporate a solenoid and limit switches as integral parts of the actuator. These valves are normally open and fail safe to the open position (GOV-1*02 and 1*06 fail closed) to provide a flow path of helium gas to the MCO under helium purge and off-normal conditions when the MCO is isolated.

MISKA, C.R.

2000-09-03T23:59:59.000Z

277

Worcester 1 Inch Solenoid Actuated Gas Operated SCHe System Valves  

SciTech Connect

1 inch Gas-operated full-port ball valves incorporate a solenoid and limit switches as integral parts of the actuator. These valves are normally open and fail safe to the open position (GOV-1*02 and 1*06 fall closed) to provide a flow path of helium gas to the MCO under helium purge and off-normal conditions when the MCO is isolated.

VAN KATWIJK, C.

2000-10-23T23:59:59.000Z

278

Worcester 1 Inch Solenoid Actuated Gas Operated SCHe System Valves  

SciTech Connect

1 inch gas-operated full-port ball valves incorporate a solenoid and limit switches as integral parts of the actuator. These valves are normally open and fail safe to the open position (GOV-1*02 and 1*06 fail closed) to provide a flow path of helium gas to the MCO under helium purge and off-normal conditions when the MCO is isolated.

MISKA, C.R.

2000-11-13T23:59:59.000Z

279

Worcester 1 Inch Solenoid Actuated Gas Operated SCHe System Valves  

SciTech Connect

1 inch Gas-operated full-port ball valves incorporate a solenoid and limit switches as integral parts of the actuator. These valves are normally open and fail safe to the open position (GOV-1*02 and 1*06 fail closed) to provide a flow path of helium gas to the MCO under helium purge and off-normal conditions when the MCO is isolated.

VAN KATWIJK, C.

2000-06-06T23:59:59.000Z

280

Valving for controlling a fluid-driven reciprocating apparatus  

DOE Patents (OSTI)

A pair of control valve assemblies for alternately actuating a pair of fluid-driven free-piston devices by using fluid pressure communication therebetween. Each control valve assembly is switched by a pressure signal depending on the state of its counterpart's piston. The communication logic is arranged to provide overlap of the forward strokes of the pistons, so that at least one of the pair will always be pressurized. Thus, uninterrupted pumping of liquid is made possible from a pair of free-piston pumps. In addition, the speed and frequency of piston stroking is entirely dependent on the mechanical power load applied. In the case of a pair of pumps, this enables liquid delivery at a substantially constant pressure over the full range of flow rates, from zero to maximum flow. Each of the valve assemblies uses an intake-exhaust valve and a signal valve with the signal valve of one pump being connected to be pressure responsive to the piston of the opposite cylinder or pump.

Whitehead, John C. (Davis, CA)

1995-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Gas lift valve failure mode analysis and the design of a thermally-actuated positive-locking safety valve  

E-Print Network (OSTI)

Gas-lifted oil wells are susceptible to failure through malfunction of gas lift valves. This is a growing concern as offshore wells are drilled thousands of meters below the ocean floor in extreme temperature and pressure ...

Gilbertson, Eric (Eric W.)

2010-01-01T23:59:59.000Z

282

THE VALVE-ACTUATED PULSE COLUMN DESIGN AND OPERATION  

SciTech Connect

A countercurrent extraction column is described which employs timed solenoid valves and pressurized feeds to provide a pulsing action to disperse the phases. The steps in the pulsing cycle are independent and thus provide greater separation of the operating variables than is possible with conventional pulse columns. The column described is particularly useful as a resesrch tool for the study of extraction mechanism although a larger installation operating on the same principles should be quite workable. The 4-stage-cycle or mixersettler type column operation has an inherent advantage in that the rapid coalescence and redispersion of phases are believed to lead to greater extraction than simple movement of a dispersed phase through a continuous medium. In addition, the sharp pulse provided should produce greater turbulence than the more conventional pulsing arrangement. Some results of operation on the extraction and stripping of uranyl nitrate using tributyl phosphate as a solvent are included. These data correspond to Metal Recovery and Erex type systems. (auth)

Burger, L.L.; Clark, L.H.

1951-12-01T23:59:59.000Z

283

Engine including hydraulically actuated valvetrain and method of valve overlap control  

DOE Patents (OSTI)

An exhaust valve control method may include displacing an exhaust valve in communication with the combustion chamber of an engine to an open position using a hydraulic exhaust valve actuation system and returning the exhaust valve to a closed position using the hydraulic exhaust valve actuation assembly. During closing, the exhaust valve may be displaced for a first duration from the open position to an intermediate closing position at a first velocity by operating the hydraulic exhaust valve actuation assembly in a first mode. The exhaust valve may be displaced for a second duration greater than the first duration from the intermediate closing position to a fully closed position at a second velocity at least eighty percent less than the first velocity by operating the hydraulic exhaust valve actuation assembly in a second mode.

Cowgill, Joel (White Lake, MI)

2012-05-08T23:59:59.000Z

284

Monovalve with integrated fuel injector and port control valve, and engine using same  

DOE Patents (OSTI)

An engine includes an engine casing that defines a hollow piston cavity separated from an exhaust passage and an intake passage by a valve seat. A gas exchange valve member is positioned adjacent the valve seat and is moveable between an open position and a closed position. The gas exchange valve member also defines an opening that opens into the hollow piston cavity. A needle valve member is positioned in the gas exchange valve member adjacent a nozzle outlet and is moveable between an inject position and a blocked position. A port control valve member, which has a hydraulic surface, is mounted around the gas exchange valve member and moveable between an intake position and an exhaust position. A pilot valve is moveable between a first position at which the port control hydraulic surface is exposed to a source of high pressure fluid, and a second position at which the port control hydraulic surface is exposed to a source of low pressure fluid.

Milam, David M. (Metamora, IL)

2001-11-06T23:59:59.000Z

285

Distributed Optimization System  

DOE Patents (OSTI)

A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

Hurtado, John E. (Albuquerque, NM); Dohrmann, Clark R. (Albuquerque, NM); Robinett, III, Rush D. (Tijeras, NM)

2004-11-30T23:59:59.000Z

286

Design and Testing of Vacuum Breaker Check Valve for Simplified Boiling Water Reactor  

Science Conference Proceedings (OSTI)

A new design of the vacuum breaker check valve was developed to replace the mechanical valve in a simplified boiling water reactor. Scaling and design calculations were performed to obtain the geometry of new passive hydraulic vacuum breaker check valve. In order to check the valve performance, a RELAP5 model of the simplified boiling water reactor system with the new valve was developed. The valve was implemented in an integral facility, PUMA and was tested for large break loss of coolant accident. (authors)

Ishii, M.; Xu, Y.; Revankar, S.T. [Purdue University, West Lafayette, IN 47907 (United States)

2002-07-01T23:59:59.000Z

287

A Main Steam Safety Valve (MSSV) With Fixed Blowdown According to ASME Section III,Part NC-7512  

Science Conference Proceedings (OSTI)

In 1986, the NRC issued the Information Notice (IN) 86-05 'Main Steam Safety Valve test failures and ring setting adjustments'. Shortly after this IN was issued, the Code was revised to require that a full flow test has to be performed on each CL.2 MSSV by the manufacturer to verify that the valve was adjusted so that it would reach full lift and thus full relieving capacity and would re-close at a pressure as specified in the valve Design Specification. In response to the concern discussed in the IN, the Westinghouse Owners Group (WOG) performed extensive full flow testing on PWR MSSVs and found that each valve required a unique setting of a combination of two rings in order to achieve full lift at accumulation of 3% and re-closing at a blowdown of 5%. The Bopp and Reuther MSSV type SiZ 2507 has a 'fixed blowdown' i.e. without any adjusting rings to adjust the 'blowdown' so that the blowdown is 'fixed'. More than 1000 pieces of this type are successfully in nuclear power plants in operation. Many of them since about 25 years. Therefore it can be considered as a proven design. It is new that an optimization of this MSSV type SiZ 2507 fulfill the requirements of part NC-7512 of the ASME Section III although there are still no adjusting rings in the flow part. In 2000, for the Qinshan Candu unit 1 and 2 full flow tests were performed with 32 MSSV type SiZ 2507 size 8'' x 12'' at 51 bar saturated steam in only 6 days. In all tests the functional performance was very stable. It was demonstrated by recording the signals lift and system pressure that all valves had acceptable results to achieve full lift at accumulation of 3% and to re-close at blowdown of 5%. This is an advantage which gives a reduction in cost for flow tests and which gives more reliability after maintenance work during outage compared to the common MSSV design with an individual required setting of the combination of the two rings. The design of the type SiZ 2507 without any adjusting rings in the flow path is presented. The stable performance depends on the interaction of flow force and spring force. The optimization of the flow path to create a suitable flow-force-curve was managed by Computational Fluid Dynamics (CFD) and flow-force-characteristic-measurements at a model 1: 2.5. The method of the flow-force-characteristic-measurement permits systematic dimensioning of valve spring forces by means of measurement of the fluid mechanical forces occurring on the valve spindle during flow. A special procedure was established to verify a spring force versus lift curve with an accuracy of 1% for each production valve. This gives high reliability at required stable performance and this can not be influenced by wrong setting of any adjusting ring during maintenance work. (authors)

Follmer, Bernhard; Schnettler, Armin [Bopp and Reuther Sicherheitsund Regelarmaturen, GmbH, Mannheim (Germany)

2002-07-01T23:59:59.000Z

288

Pathwise Optimization for Optimal Stopping Problems  

Science Conference Proceedings (OSTI)

We introduce the pathwise optimization (PO) method, a new convex optimization procedure to produce upper and lower bounds on the optimal value (the “price”) of a high-dimensional optimal stopping problem. The PO method builds on a dual characterization ... Keywords: American options, Bermudian options, dynamic programming, optimal control, optimal stopping

Vijay V. Desai; Vivek F. Farias; Ciamac C. Moallemi

2012-12-01T23:59:59.000Z

289

Quasi-Static Hydraulic Control Systems and Energy Savings Potential Using Independent Metering Four-Valve Assembly Configuration .  

E-Print Network (OSTI)

??In this research, the four valve independent metering configuration is to be investigated. The Independent metering concept will be emphasized and compared to spool valve… (more)

Shenouda, Amir

2006-01-01T23:59:59.000Z

290

Search via Probability Algorithm for Single-Objective Optimization ...  

E-Print Network (OSTI)

suggest a new approach to find optimal solutions, the Search via Probability (SP) algorithm. ... searching an optimal solution the first time for each performance.

291

Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide)  

E-Print Network (OSTI)

A compact printable microfluidic valve composed of poly(N-isopropylacrylamide) has been designed, fabricated, and tested. The design of the valve consists of filling microwells with poly(NIPAAm) and bonding PDMS channels ...

Reticker-Flynn, Nathan Edward

2008-01-01T23:59:59.000Z

292

Processing of prosthetic heart valve sounds for single leg separation classification  

Science Conference Proceedings (OSTI)

People with serious heart conditions have had their expected life span extended considerably with the development of the prosthetic heart valve especially with the great strides made in valve design. Even though the designs are extremely reliable

J. V. Candy; H. E. Jones

1995-01-01T23:59:59.000Z

293

Drive piston assembly for a valve actuator assembly  

DOE Patents (OSTI)

A drive piston assembly is provided that is operable to selectively open a poppet valve. The drive piston assembly includes a cartridge defining a generally stepped bore. A drive piston is movable within the generally stepped bore and a boost sleeve is coaxially disposed with respect to the drive piston. A main fluid chamber is at least partially defined by the generally stepped bore, drive piston, and boost sleeve. First and second feedback chambers are at least partially defined by the drive piston and each are disposed at opposite ends of the drive piston. At least one of the drive piston and the boost sleeve is sufficiently configured to move within the generally stepped bore in response to fluid pressure within the main fluid chamber to selectively open the poppet valve. A valve actuator assembly and engine are also provided incorporating the disclosed drive piston assembly.

Sun, Zongxuan (Troy, MI)

2010-02-23T23:59:59.000Z

294

Technical Repair Guidelines for the Limitorque Model SMB-00 Valve Actuator  

Science Conference Proceedings (OSTI)

This technical repair guideline (TRG) is the second in a series of documents devoted to comprehensive maintenance and repair of the motor-operated Limitorque SMB-00 valve actuator. The Limitorque SMB-00 valve actuator is mounted on a nonrotating rising stem valve and is applicable to other types of valves and installation arrangements. This report was written with the latest available information, however, changes to the actuator's design, parts availability, etc. may supersede this document but will not...

1995-06-30T23:59:59.000Z

295

Water Consumption from Freeze Protection Valves for Solar Water Heating Systems  

DOE Green Energy (OSTI)

Conference paper regarding research in the use of freeze protection valves for solar domestic water heating systems in cold climates.

Burch, J.; Salasovich, J.

2005-12-01T23:59:59.000Z

296

Surfacing of the parts of Christmas tree valves  

SciTech Connect

The authors discuss the strengthening of Christmas trees for service conditions, in particular, the method of plasma spraying of the sealing surfaces of the gates of the valves with hard corrosion resistant alloys. Most frequently, cobalt- (stellite), nickel- (colmonoy), and iron-base alloys are used for surfacing. A plan is shown of the area for plasma surfacing in one of the petroleum machinery plants. It is found that the hardening of the sealing surface of gate valve parts by plasma powder surfacing with self-fluxing nickel alloys increases the reliability and life of well-head equipment.

Mordynskii, V.B.; Barsukov, V.P.; Iskakhov, A.R.; Komarcheva, E.S.

1987-07-01T23:59:59.000Z

297

Probability of Safety Valve Failure-to-Reseat Following Steam and Liquid Relief: Quantitative Expert Elicitation  

Science Conference Proceedings (OSTI)

This report describes a quantitative expert elicitation to assist in the determination of the failure probability of safety valves to reseat following steam and/or liquid relief. The expert elicitation process improves the estimation of the safety valve failure-to-reseat probability and is based on expert judgment, safety valve testing programs, and experience.

2004-08-31T23:59:59.000Z

298

Worcester 1 Inch Solenoid Actuated Gas Operated VPS System Ball Valve  

SciTech Connect

1 inch Gas-operated full-port ball valve incorporates a solenoid and limit switches as integral parts of the actuator. The valve is normally open and fails safe to the closed position. The associated valve position switch is class GS.

VAN KATWIJK, C.

2000-06-06T23:59:59.000Z

299

Worcester 1 Inch Solenoid Actuated Gas Operated VPS System Ball Valve  

Science Conference Proceedings (OSTI)

1 inch Gas-operated full-pod ball valve incorporates a solenoid and limit switches as integral park of the actuator. The valve is normally open and fails safe to the closed position. The associated valve position switch is class GS.

MISKA, C.R.

2000-11-13T23:59:59.000Z

300

E85 Optimized Engine through Boosting, Spray-Optimized DIG, VCR and Variable Valvetrain  

DOE Green Energy (OSTI)

The use of biofuels for internal combustion engines has several well published advantages. The biofuels, made from biological sources such as corn or sugar cane, are renewable resources that reduce the dependence on fossil fuels. Fuels from agricultural sources can therefore reduce a countries energy dependency on other nations. Biofuels also have been shown to reduce CO2 emissions into the atmosphere compared to traditional fossil based fuels. Because of these benefits several countries have set targets for the use of biofuels, especially ethanol, in their transportation fuels. Small percentages of ethanol are common place in gasoline but are typically limited to 5 to 8% by volume. Greater benefits are possible from higher concentrations and some countries such as the US and Sweden have encouraged the production of vehicles capable of operating on E85 (85% denatured ethanol and 15% gasoline). E85 capable vehicles are normally equipped to run the higher levels of ethanol by employing modified fuel delivery systems that can withstand the highly corrosive nature of the alcohol. These vehicles are not however equipped to take full advantage of ethanol's properties during the combustion process. Ethanol has a much higher blend research octane number than gasoline. This allows the use of higher engine compression ratios and spark advance which result in more efficient engine operation. Ethanol's latent heat of vaporization is also much higher that gasoline. This higher heat of vaporization cools the engine intake charge which also allows the engine compression ratio to be increased even further. An engine that is optimized for operation on high concentrations of ethanol therefore will have compression ratios that are too high to avoid spark knock (pre-ignition) if run on gasoline or a gasoline/ethanol blend that has a low percentage alcohol. An engine was developed during this project to leverage the improved evaporative cooling and high octane of E85 to improve fuel economy and offset E85's lower energy content. A 2.0 L production Direct Injection gasoline, (DIg) engine employing Dual Independent Cam Phasing, (DICP) and turbo charging was used as the base engine. Modified pistons were used to increase the geometric compression ratio from 9.2:1 to 11.85:1 by modifying the pistons and adding advanced valvetrain to proved control of displacement and effective compression ratio through valve timing control. The advanced valvetrain utilized Delphi's two step valvetrain hardware and intake cam phaser with increased phasing authority of 80 crank angle degrees. Using this hardware the engine was capable of operating knock free on all fuels tested from E0-E85 by controlling effective compression ratio using a Late Intake Valve Closing, (LIVC) strategy. The LIVC strategy results in changes in the trapped displacement such that knock limited torque for gasoline is significantly lower than E85. The use of spark retard to control knock enables higher peak torque for knock limited fuels, however a loss in efficiency results. For gasoline and E10 fuels, full effective displacement could not be reached before spark retard produced a net loss in torque. The use of an Early Intake Valve Closing, (EIVC) strategy resulted in an improvement of engine efficiency at low to mid loads for all fuels tested from E0- E85. Further the use of valve deactivation, to a single intake valve, improved combustion stability and enabled throttle-less operation down to less than 2 bar BMEP. Slight throttling to trap internal residual provided additional reductions in fuel consumption. To fully leverage the benefits of E85, or ethanol blends above E10, would require a vehicle level approach that would take advantage of the improved low end torque that is possible with E85. Operating the engine at reduced speeds and using advanced transmissions (6 speeds or higher) would provide a responsive efficient driving experience to the customer. The vehicle shift and torque converter lockup points for high ethanol blends could take advantage of the significant efficiency ad

Keith Confer; Harry Husted

2011-05-31T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Workshop on gate valve pressure locking and thermal binding  

SciTech Connect

The purpose of the Workshop on Gate Valve Pressure Locking and Thermal Binding was to discuss pressure locking and thermal binding issues that could lead to inoperable gate valves in both boiling water and pressurized water reactors. The goal was to foster exchange of information to develop the technical bases to understand the phenomena, identify the components that are susceptible, discuss actual events, discuss the safety significance, and illustrate known corrective actions that can prevent or limit the occurrence of pressure locking or thermal binding. The presentations were structured to cover U.S. Nuclear Regulatory Commission staff evaluation of operating experience and planned regulatory activity; industry discussions of specific events, including foreign experience, and efforts to determine causes and alleviate the affects; and valve vendor experience and recommended corrective action. The discussions indicated that identifying valves susceptible to pressure locking and thermal binding was a complex process involving knowledge of components, systems, and plant operations. The corrective action options are varied and straightforward.

Brown, E.J.

1995-07-01T23:59:59.000Z

302

Aging and service wear of air-operated valves used in safety-related systems at nuclear power plants  

SciTech Connect

Air-operated valves (AOVs) are used in a variety of safety-related applications at nuclear power plants. They are often used where rapid stroke times are required or precise control of the valve obturator is required. They can be designed to operate automatically upon loss of power, which is often desirable when selecting components for response to design basis conditions. The purpose of this report is to examine the reported failures of AOVs and determine whether there are identifiable trends in the failures related to predictable causes. This report examines the specific components that comprise a typical AOV, how those components fail, when they fail, and how such failures are discovered. It also examines whether current testing frequencies and methods are effective in predicting such failures.

Cox, D.F.; McElhaney, K.L.; Staunton, R.H.

1995-05-01T23:59:59.000Z

303

Performance and Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

and Optimization Performance and Optimization Compiler Comparisons Using a set of benchmarks described below, different optimization options for the different compilers on...

304

Optimization Online - A Polynomial Time Constraint Reduced ...  

E-Print Network (OSTI)

Aug 26, 2013 ... The use of preconditioning for training support vector machines. Master's thesis, Applied Mathematics and Scientific Computing Program, ...

305

The Time Dependent Traveling Salesman Problem - Optimization ...  

E-Print Network (OSTI)

inequalities can be expressed in terms of the TDTSP variables as follows: ? j?S x0 ... at a vertex in S or it must enter S no later than layer n ? |S|. ..... The search.

306

Magnetism reflectometer study shows LiF layers improve efficiency in spin valve devices  

Science Conference Proceedings (OSTI)

New, more efficient materials for spin valves - a device used in magnetic sensors, random access memories, and hard disk drives - may be on the way based on research using the magnetism reflectometer at Oak Ridge National Laboratory (ORNL). Spin valve devices work by means of two or more conducting magnetic material layers that alternate their electrical resistance depending on the layers alignment. Giant magnetoresistance is a quantum mechanical effect first observed in thin film structures about 20 years ago. The effect is observed as a significant change in electrical resistance, depending on whether the magnetization of adjacent ferromagnetic layers is in a parallel or an antiparallel magnetic alignment. 'What we are doing here is developing new materials. The search for new materials suitable for injecting and transferring carriers with a preferential spin orientation is most important for the development of spintronics,' said Valeria Lauter, lead instrument scientist on the magnetism reflectometer at the Spallation Neutron Source (SNS), who collaborated on the experiment. The researchers discovered that the conductivity of such materials is improved when an organic polymer semiconductor layer is placed between the magnetic materials. Organic semiconductors are now the material of choice for future spin valve devices because they preserve spin coherence over longer times and distances than conventional semiconductors. While research into spin valves has been ongoing, research into organic semiconductors is recent. Previous research has shown that a 'conductivity mismatch' exists in spin valve systems in which ferromagnetic metal electrodes interface with such organic semiconductors as Alq3 ({pi}-conjugated molecule tris(8-hydroxy-quinoline) aluminium). This mismatch limits the efficient injection of the electrons from the electrodes at the interface with the semiconductor material. However, lithium fluoride (LiF), commonly used in light-emitting diodes, has been found to enhance the injection of electrons through the semiconductor. Researchers from the University of Alabama and ORNL used polarized neutrons at the magnetism reflectometer at SNS to investigate the electronic, magnetic, and structural properties of the electrodes in a novel system. In this system, the magnetic layers cobalt and Ni{sub 80}Fe{sub 20} are interfaced with spacer layers composed of the organic semiconductor Alq3. A coupling layer of LiF is inserted to separate the magnetized layers from the semiconductor. 'ALQ3 is an organic semiconductor material,' said Lauter. 'Normally in these systems a first magnetic layer is grown on a hard substrate so that one can get the controlled magnetic parameters. Then you grow the organic semiconductor layer, followed by another magnetic material layer, such as cobalt.' In addition to determining the effect of the LiF layers on the efficiency of the electron injection, the researchers wanted to determine the magnetic properties of the cobalt and Ni{sub 80}Fe{sub 20} as well as the interfacial properties: whether there is interdiffusion of cobalt through the LiF layer to the semiconductor, for example. The researchers used polarized neutrons at beam line 4A to probe the entire, layer-by-layer assembly of the system. 'Reflectometry with polarized neutrons is a perfect method to study thin magnetic films,' Lauter said. 'These thin films - if you put one on a substrate, you see it just like a mirror. However, this mirror has a very complicated internal multilayer structure. The neutrons look inside this complicated structure and characterize each and every interface. Due to the depth sensitivity of the method, we measure the structural and magnetic properties of each layer with the resolution of 0.5 nm. The neutron scattering results found that inserting LiF as a barrier significantly improves the quality of the interface, increasing the injection of electrons from the magnetic layer through the organic semiconductor in the spin valve and enhancing the overall properties of the system. In related work the magneti

Bardoel, Agatha A [ORNL; Lauter, Valeria [ORNL; Szulczewski, Greg J [ORNL

2012-01-01T23:59:59.000Z

307

Optimization Online - Stochastic Optimization Approach to Water ...  

E-Print Network (OSTI)

Mar 18, 2012 ... Optimization Online. Stochastic Optimization Approach to Water Management in Cooling-Constrained Power Plants. Juan M. Salazar(juan ...

308

Optimization Online - Global Optimization Submissions - 2011  

E-Print Network (OSTI)

Optimization and homotopy methods for the Gibbs free energy of magmatic mixtures ... On DC. optimization algorithms for solving minmax flow problems

309

Learning-based ship design optimization approach  

Science Conference Proceedings (OSTI)

With the development of computer applications in ship design, optimization, as a powerful approach, has been widely used in the design and analysis process. However, the running time, which often varies from several weeks to months in the current computing ... Keywords: Machine learning, Multi-objective optimization, Ship design, Structure analysis, Structure optimization

Hao Cui; Osman Turan; Philip Sayer

2012-03-01T23:59:59.000Z

310

Interplanetary trajectory optimization with swing-bys using evolutionary multi-objective optimization  

Science Conference Proceedings (OSTI)

Interplanetary trajectory optimization studies mostly considered a single objective of minimizing the travel time between two planets or the launch velocity of spacecraft at the departure planet. In this paper, we have considered a simultaneous minimization ... Keywords: optimization

Nikhil Padhye

2008-07-01T23:59:59.000Z

311

Risk-averse periodic preventive maintenance optimization.  

E-Print Network (OSTI)

??We consider a class of periodic preventive maintenance (PM) optimization problems, for a single piece of equipment that deteriorates with time or use, and can… (more)

Singh, Inderjeet,1978-

2011-01-01T23:59:59.000Z

312

Analysis of oil-pipeline distribution of multiple products subject to delivery time-windows  

E-Print Network (OSTI)

This dissertation defines the operational problems of, and develops solution methodologies for, a distribution of multiple products into oil pipeline subject to delivery time-windows constraints. A multiple-product oil pipeline is a pipeline system composing of pipes, pumps, valves and storage facilities used to transport different types of liquids. Typically, products delivered by pipelines are petroleum of different grades moving either from production facilities to refineries or from refineries to distributors. Time-windows, which are generally used in logistics and scheduling areas, are incorporated in this study. The distribution of multiple products into oil pipeline subject to delivery time-windows is modeled as multicommodity network flow structure and mathematically formulated. The main focus of this dissertation is the investigation of operating issues and problem complexity of single-source pipeline problems and also providing solution methodology to compute input schedule that yields minimum total time violation from due delivery time-windows. The problem is proved to be NP-complete. The heuristic approach, a reversed-flow algorithm, is developed based on pipeline flow reversibility to compute input schedule for the pipeline problem. This algorithm is implemented in no longer than O(T*E) time. This dissertation also extends the study to examine some operating attributes and problem complexity of multiple-source pipelines. The multiple-source pipeline problem is also NP-complete. A heuristic algorithm modified from the one used in single-source pipeline problems is introduced. This algorithm can also be implemented in no longer than O(T*E) time. Computational results are presented for both methodologies on randomly generated problem sets. The computational experience indicates that reversed-flow algorithms provide good solutions in comparison with the optimal solutions. Only 25% of the problems tested were more than 30% greater than optimal values and approximately 40% of the tested problems were solved optimally by the algorithms.

Jittamai, Phongchai

2004-12-01T23:59:59.000Z

313

System for minimizing valve throttling losses in a steam turbine power plant  

SciTech Connect

A system which integrates the controls of a steam turbine power plant for minimizing power plant energy losses substantially caused by steam flow valve throttling is disclosed. The steam turbine power plant includes boiler pressure controls for controlling the boiler throttle pressure of a steam producing boiler and turbine-generator controls for positioning a plurality of turbine steam admission values to regulate the steam flow conducted through a steam turbine which governs the electrical energy generated by an electrical generator at a desired power generation level. The turbine-generator controls predetermine a plurality of valve position states to establish a predetermined valve grouping sequential positioning pattern for the steam admission valves to regulate steam flow through the steam turbine across the range of power generation, each predetermined state substantially corresponding to a minimum of valve throttling losses. The steam admission valves may be positioned at a present valve position state, which is other than one of the predetermined states, as a result of a change in desired power generation level. The disclosed system responds to this condition by governing the boiler pressure controls to adjust the boiler throttle pressure at a desired rate and in a direction to cause steam admission valves to be repositioned according to the sequential positioning pattern to a selected one of the predetermined efficient valve position states. The repositioning of the steam admission valves is performed by maintaining the generated energy substantially at the new desired power generation level.

Stern, L.P.; Johnson, S.J.

1979-12-18T23:59:59.000Z

314

System to inject steam and produce oil from the same wellbore through downhole valve switching. Final report  

SciTech Connect

Through direct contacts with many California Operators, the potential market for this technology and hardware was more closely defined. The largest market might be for re-entry into existing but shut-in wells, equipped with 7{double_prime}OD cemented casings, for which a suitable configuration was designed. For field-testing any prototype Downhole equipment, however, Operators and Service Companies prefer to start with a new well, for better control of the well characteristics. In the relatively shallow reservoirs where Steam injection is currently used with success, the additional drilling cost, in soft formations, is sufficiently small that this became the main design case. Substantial savings were obtained by reducing the number of Downhole valves from two to one and by replacing the twin hydraulically-controlled ball or flapper-type valves with a single sliding sleeve valve, operated by wireline. Laboratory tests conducted at UC-Berkeley confirmed the satisfactory operation of this type of valve with wet steam over extended periods. Low reservoir pressures dictated the use of artificial lift methods, with rod pumps considered the most economical. The availability of live steam downhole at all times is, however, a major advantage which led to the selection of a combined method of artificial lift: (1) steam-lift of the produced fluids up to the kick-off point of the medium curvature drainholes, (2) dumping of the produced fluids into a vertical separator/sump below the kick-off points, (3) vertical rod pumping of the liquid phases from the downhole separator/sump to the surface through a dedicated production tubing.

Not Available

1994-10-01T23:59:59.000Z

315

Application of a Plasma Powder Welding to engine valves  

SciTech Connect

In hardfacing of automobile engine valves made of heat resisting steel such as 21-4N, conventional oxy-acetylene gase welding has been currently conducted manually by well trained operators because of using cast Stellite rods as the filler. In accordance with the strong demands of automatic welding, the authors newly developed an automatically controlled Plasma Powder Welding (PPW) system. This system is characterized by the application of a high thermal density plasma arc as heat source and by using power filler which melts more easily than bar cast rods. Moreover, this PPW system has been applied to the automotive engine valve production line and resulted in the great contribution to manpower saving.

Takeuchi, Y.; Nagata, M.

1985-01-01T23:59:59.000Z

316

Distributed rate allocation for inelastic flows: Optimization frameworks, optimality conditions, and optimal algorithms  

E-Print Network (OSTI)

Abstract—A common assumption behind the recent surge in research activities on network utility maximization is that the traffic flows are elastic, which implies that the utility functions are concave and there are no hard limits on the rate allocated to each flow. These critical assumptions lead to the tractability of the analytic models of utility maximization, but also limits the applicability of the resulting rate allocation protocols. This paper focuses on inelastic flows and removes these restrictive and often invalid assumptions. We present several optimization frameworks, optimality conditions, and optimal algorithms. First we consider nonconcave utility functions, which turn utility maximization into nonconvex, constrained optimization problems that are well-known to be extremely difficult. We first show a surprising result that under certain conditions, the standard pricing algorithm for rate allocation will still converge to the globally optimal rate allocation. When the existing distributed algorithm fails, we present a new algorithm that produces the globally optimal rate allocation, with the worst case complexity being polynomial time in the number of users but exponential time in the number of links. In the second part of the paper, we provide a general problem formulation of rate allocation among time-sensitive flows from real-time and streaming applications, as well as a decomposition into subproblems coordinated by pricing. After simplifying the subproblems by leveraging the optimization structures, we highlight the difficult issues of causality and time-scale, and propose an effective pricing-based heuristics for admission control and an optimal algorithm for a special case formulation.

Mung Chiang; Shengyu Zhang; Prashanth H

2005-01-01T23:59:59.000Z

317

Valve Regulated Lead Acid (VRLA) Battery Qualification Assessment  

Science Conference Proceedings (OSTI)

Valve-regulated lead acid (VRLA) batteries have been proposed as a prospective dc power source for Class 1E service in passive nuclear plants. However, they are not currently covered by IEEE Standard 535, which addresses qualification for this service. Furthermore, there are reports of significant failure modes or mechanisms beyond the predominant failure mode of grid corrosion of the positive plate associated with vented lead acid (VLA) batteries.

2009-11-06T23:59:59.000Z

318

Application of Nanocoatings for Erosion Protection of Valve Stems  

Science Conference Proceedings (OSTI)

Damage in steam turbine valve stems is attributed to erosion from the impingement of spalled oxides present in the high-temperature flowing steam environment. Utilities and turbine engineers are currently managing the erosion and damage issues through component replacement (in some extreme cases, with component lives shorter than one year). With limited success, numerous materials have been examined as alternatives to extend component life. Erosion-resistant nanocoatings have shown superior performance t...

2010-12-19T23:59:59.000Z

319

Diffusion based degradation mechanisms in giant magnetoresistive spin valves  

Science Conference Proceedings (OSTI)

Spin valve systems based on the giant magnetoresistive effect as used, for example, in hard disks and automotive applications consist of several functional metallic thin film layers. We have identified by secondary ion mass spectrometry two main degradation mechanisms: one is related to oxygen diffusion through a protective cap layer and the other one is interdiffusion directly at the functional layers of the giant magnetoresistive stack. By choosing a suitable material as cap layer (TaN), the oxidation effect can be suppressed.

Hawraneck, Matthias [Department of Sense and Control, Infineon Technologies AG, 85579 Neubiberg (Germany); Institute for Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany); Zimmer, Juergen; Raberg, Wolfgang; Pruegl, Klemens; Schmitt, Stephan; Bever, Thomas [Department of Sense and Control, Infineon Technologies AG, 85579 Neubiberg (Germany); Flege, Stefan; Alff, Lambert [Institute for Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

2008-07-07T23:59:59.000Z

320

Steam Turbine Valve Actuator Condition Assessment: 2013 Update  

Science Conference Proceedings (OSTI)

This report provides nuclear and fossil plant personnel with current information on the inspection and assessment of steam turbine valve actuators. It covers the actuators that are typically found on the turbines of the two major U.S. original equipment manufacturers (OEMs), as well as those of several non-U.S. OEMs. The scope encompasses both mechanical hydraulic control (MHC) and electronic hydraulic control (EHC) types of hydraulic ...

2013-07-25T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Safety and Relief Valve Testing and Maintenance Guide  

Science Conference Proceedings (OSTI)

This guide gives a broad overview of self actuated and power operated pressure relief devices (PRDs) -- safety, relief, safety relief, and power-operated relief valves -- and their application and maintenance. The non-reclosing devices, like the rupture discs, are outside the scope of this guide. The information in this guide, though directed towards the nuclear power plant personnel, will assist all power plant personnel responsible for the maintenance of PRDs. This guide can also be used by training in...

1996-10-02T23:59:59.000Z

322

The lubrication of engine valve trains equipped with ceramicized followers  

Science Conference Proceedings (OSTI)

The valve train wear characteristics of motored 2.2l and 2.3l engines were examined using ceramic and conventional metal cam followers. Under regular wear conditions with fully formulated motor oils, minimal wear was observed on the metal cam lobes running with either the ceramicized or metal followers. Running under chemically accelerated wear conditions with low quality oil, however, cam lobe wear with ceramicized followers was observed to be significantly less than that with metal followers. The difference in wear was diminished when testing high quality oils under chemically accelerated conditions. Typical testing revealed that the metal follower pads quickly developed considerable wear in a characteristic pattern, while the ceramic followers pads quickly developed considerable were in a characteristic pattern, while the ceramic followers exhibited only slight polishing. Scanning electron photographs revealed details of the used ceramic surfaces, and that wear took place by polishing and by intergranular fracture with subsequent material removal. Engine wear is a major factor that limits the life of today's passenger cars. Particularly for the newer models that have smaller but higher speed and output engines incorporating current designs such as overhead camshafts, 4-valves per cylinder and turbochargers, the valve train represents one of the highest wear components within an engine. In light of the trend towards extended drivetrain warranties, there is a strong demand for lubricant suppliers to develop engine oils with improved antiwear performance. In a parallel effort, automotive engine and component manufacturers are enhancing valve train durability with technologies that include roller followers and the use of advanced ceramic materials.

Blahey, A.G.; Habeeb, J.J.; Rogers, W.N.< 110> The lubrication of engine valve trains equipped with ceramicized followers.

1990-01-01T23:59:59.000Z

323

Expanding Robust HCCI Operation with Advanced Valve and Fuel Control Technologies Pub ID 38707 Title Expanding Robust HCCI Operation with Advanced Valve and Fuel Control Technologies Status Distributed Communication Type ORNL report ORNL Review? Scientific communication that requires ORNL review Information Category Protected CRADA Information ORNL Report Classification Final Expanding Robust HCCI Operation with Advanced Valve and Fuel Control Technologies  

SciTech Connect

Delphi Automotive Systems and ORNL established this CRADA to advance the commercialization potential of the homogeneous charge compression ignition (HCCI) advanced combustion strategy for gasoline engine platforms. HCCI combustion has been shown by others to produce high diesel-like efficiency on a gasoline engine platform while simultaneously producing low NOX and particulate matter emissions. However, the commercialization barriers that face HCCI combustion are significant, with requirements for a more active engine control system, likely with next-cycle closed-loop feedback control, and with advanced valve train technologies to enable negative valve overlap conditions. In the partnership between Delphi and ORNL, each organization brought a unique and complementary set of skills to the project. Delphi has made a number of breakthroughs with production-intent valve train technologies and controls in recent years to make a part time production-intent HCCI engine plausible. ORNL has extensive knowledge and expertise with HCCI combustion, and also has a versatile research engine with hydraulic valve actuation (HVA) that is useful for guiding production of a cam-based HCCI system. Partnering these knowledge bases and capabilities was essential towards making progress to better understand HCCI combustion and the commercialization barriers that it faces. ORNL and Delphi maintained strong collaboration throughout the project. Meetings were held regularly, with additional reports, presentations, and meetings as necessary to maintain progress. Delphi provided guidance to ORNL regarding operational strategies to investigate on their single-cylinder research engine with HVA and data from their experimental multi-cylinder engine for modeling. ORNL provided single-cylinder engine data and modeling results.

Szybist, J.P.; Confer, K. (Delphi Automotive Systems)

2012-09-11T23:59:59.000Z

324

Sliding-gate valve for use with abrasive materials  

DOE Patents (OSTI)

The invention is a flow and pressure-sealing valve for use with abrasive solids. The valve embodies special features which provide for long, reliable operating lifetimes in solids-handling service. The valve includes upper and lower transversely slidable gates, contained in separate chambers. The upper gate provides a solids-flow control function, whereas the lower gate provides a pressure-sealing function. The lower gate is supported by means for (a) lifting that gate into sealing engagement with its seat when the gate is in its open and closed positions and (b) lowering the gate out of contact with its seat to permit abrasion-free transit of the gate between its open and closed positions. When closed, the upper gate isolates the lower gate from the solids. Because of this shielding action, the sealing surface of the lower gate is not exposed to solids during transit or when it is being lifted or lowered. The chamber containing the lower gate normally is pressurized slightly, and a sweep gas is directed inwardly across the lower-gate sealing surface during the vertical translation of the gate.

Ayers, Jr., William J. (Morgantown, WV); Carter, Charles R. (Fairmont, WV); Griffith, Richard A. (Morgantown, WV); Loomis, Richard B. (Bruceton Mills, WV); Notestein, John E. (Morgantown, WV)

1985-01-01T23:59:59.000Z

325

Double Shell Tank (DST) Transfer Valving Subsystem Specification  

Science Conference Proceedings (OSTI)

This specification establishes the performance requirements and provides references to the requisite codes and standards to be applied during design of the Double-Shell Tank (DST) Transfer Valving Subsystem that supports the first phase of Waste Feed Delivery. This specification establishes the performance requirements and provides references to the requisite codes and standards to be applied during design of the Double-Shell Tank (DST) Transfer Valving Subsystem that supports the first phase of Waste Feed Delivery (WFD). The DST Transfer Valving Subsystem routes waste and other media (e.g., diluent, flush water, filtered raw water) among DSTs and from the low-activity waste (LAW) and high-level waste (HLW) feed staging tanks to the River Protection Project (RPP) Privatization Contractor facility, where it will be processed into an immobilized waste form. This specification is intended to be the basis for new projects/installations (W-521, etc.). This specification is not intended to retroactively affect previously established project design criteria without specific direction by the program.

GRAVES, C.E.

2000-03-22T23:59:59.000Z

326

Previous work conducted in the laboratory demonstrated optimal control of refrigerant flow and airflow for a breadboard CVSHP (Miller 1987a). This previous work was continued in the present study by investigation  

E-Print Network (OSTI)

#12;Previous work conducted in the laboratory demonstrated optimal control of refrigerant flow optimal refrigerant flow and airflow control settings. Previous studies by Tanaka and Yamanaka (1982 pump were replaced with fine metering hand valves having variable flow area for both heating

Oak Ridge National Laboratory

327

A tritium-compatible piezoelectric valve for the tokamak fusion test reactor  

SciTech Connect

This work describes modifications made to a commercial piezoelectric valve to make it sufficiently tritium compatible for the TFTR trritium injection scenario. The results of testing the valve for leakage and performance following a series of progressively more severe tritium exposures are also presented. Finally, a proposal for a totally radiation-compatible piezoelectric valve, suitable for tritium-burning fusion machines of the future, is decribed. 9 refs., 2 figs., 1 tab.

Coffin, D.O.; Cole, S.P.; Wilhelm, R.C.

1988-02-01T23:59:59.000Z

328

Investigation of Main Steam Safety Valve Seat/Nozzle Surface Treatments  

Science Conference Proceedings (OSTI)

This report discusses continued research in evaluating the main steam safety valve (MSSV) high first lift phenomenon (seat sticking) experienced in some Dresser 3700 series steam safety valves. Previous EPRI research (Report TR-113560) concluded that the high first lift phenomenon is the result of adhesion of the valve disk to the nozzle seat resulting in additional opening force to separate the disk from the nozzle. Replacement of the disks with disks incorporating pre-oxidized Inconel X-750 material on...

2003-05-30T23:59:59.000Z

329

Computer Based Training: Engineering Technical Training Modules - Valve Actuator v1.0  

Science Conference Proceedings (OSTI)

Valve Actuator ETTM, Version 1.0 is a computer-based training module that allows users to access training when desired and review it at their own pace. The purpose of this training module is to provide a basic understanding of the various types of power valve actuators used in nuclear power plants and their characteristics. This module will also provide an understanding of valve actuator applications, selection, accessory requirements, and capabilities. This computer-based training (CBT) module is intend...

2009-12-04T23:59:59.000Z

330

Computer Based Training: Engineering Technical Training Module (ETTM) Relief and Safety Valves v1.0  

Science Conference Proceedings (OSTI)

Relief and Safety Valves ETTM, Version 1.0 is a computer45based training module that allows users to access training when desired and review it at their own pace. This module provides information about the types of valves, requirements surrounding their performance, characteristics and selection of these valves, as well as testing requirements. Additionally, it describes design considerations and system interactions. This training should be used for position specific and/or continuing training for indivi...

2009-11-02T23:59:59.000Z

331

Safety Valve Performance Considerations During High-Pressure Station Black-Out Severe Accidents  

Science Conference Proceedings (OSTI)

An assessment of the operating history and test performance of pressurizer safety valves (PSVs) and main steam safety valves (MSSVs) has led to new conclusions on their expected performance during high-pressure station blackout (SBO) severe accident conditions. This report updates conclusions documented in Volume I, focusing on thermal-hydraulic considerations surrounding the reactor coolant system response to an SBO and valve lifts during an SBO event. The report also reconsiders PSV and MSSV tests and ...

1998-01-02T23:59:59.000Z

332

EPRI/C-E PWR Safety Valve Test Report, Volume 10: Piping Structural Response Results  

Science Conference Proceedings (OSTI)

EPRI at the request of the PWR Utilities developed an overall program for the testing of PWR primary system safety and relief valves. This program was in response to NUREG 0578 Item 2.1.2 and NUREG 0737 Item II.D.l.A requirements.This report documents the results of safety valve testing performed as part of the overall program at the EPRI/C-E Valve Test Facility located at Combustion Engineering's Kreisinger Development Laboratory, Windsor, Connecticut. Seven safety valves ...

1983-04-01T23:59:59.000Z

333

A means for positively seating a piezoceramic element in a piezoelectric valve during inlet gas injection  

DOE Patents (OSTI)

This invention is comprised of a piezoelectric valve in a gas delivery system which includes a piezoceramic element bonded to a valve seal and disposed over a valve seat, and retained in position by an O-ring and a retainer; and insulating ball normally biased by a preload spring against the piezoceramic element; and inlet gas port positioned such that upon admission of inlet gas into the valve. The piezoceramic element is positively seated. The inelt gas port is located only on the side of the piezoceramic element opposite the seal.

Wright, K.E.

1993-12-31T23:59:59.000Z

334

Optimization Online - Nonlinear Optimization Submissions - 2012  

E-Print Network (OSTI)

Mariano Beguerisse-Díaz, Baojun Wang, Radhika Desikan, Mauricio Barahona. Unconstrained Optimization Globally Convergent Evolution Strategies and ...

335

Optimization Online - Robust Optimization Submissions - 2011  

E-Print Network (OSTI)

Sanjay Mehrotra, He Zhang. Robust Energy Cost Optimization of Water Distribution System with Uncertain Demand Alexander Goryashko, Arkadi Nemirovski.

336

Optimization Online - Robust Optimization Submissions - 2013  

E-Print Network (OSTI)

Robust Optimization Submissions - 2013. January 2013. Robust Least Square Semidefinite Programming with Applications to Correlation Stress Testing

337

Optimization Online - Optimizing Trading Decisions for Hydro ...  

E-Print Network (OSTI)

Dec 10, 2011 ... Optimizing Trading Decisions for Hydro Storage Systems using Approximate ... Keywords: OR in Energy, Approximate Dynamic Programming, ...

338

Performance and Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

1-800-66-NERSC, option 3 or 510-486-8611 Home For Users Computational Systems Edison Performance and Optimization Performance and Optimization Note: all the performance...

339

Observation and implications of magnetic domains in lateral spin valves  

Science Conference Proceedings (OSTI)

Co/Cu/Co lateral spin valves (LSV), with Co being the topmost layer, are in situ prepared and measured under ultrahigh vacuum conditions. The clean process yields a non-local spin signal of 0.9 m{Omega}. Scanning electron microscopy with polarization analysis (SEMPA) reveals domain structures in both magnetic electrodes that depend on the LSV dimensions. The spin signal correlates to SEMPA images as well as the anisotropic magnetoresistance of both Co magnets, revealing a strong impact of multi-domain states on the spin signal.

Mennig, J.; Matthes, F.; Buergler, D. E.; Schneider, C. M. [Peter Gruenberg Institute, Electronic Properties (PGI-6) and Juelich-Aachen Research Alliance, Fundamentals of Future Information Technology (JARA-FIT), Forschungszentrum Juelich GmbH, Juelich D-52425 (Germany)

2012-04-01T23:59:59.000Z

340

Endothelial Progenitor Cells as a Sole Source for Ex Vivo Seeding of Tissue-Engineered Heart Valves  

E-Print Network (OSTI)

Purposes: We investigated whether circulating endothelial progenitor cells (EPCs) can be used as a cell source for the creation of a tissue-engineered heart valve (TEHV). Methods: Trileaflet valved conduits were fabricated ...

Sales, Virna L.

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Automated high-throughput flow-through real-time diagnostic system  

DOE Patents (OSTI)

An automated real-time flow-through system capable of processing multiple samples in an asynchronous, simultaneous, and parallel fashion for nucleic acid extraction and purification, followed by assay assembly, genetic amplification, multiplex detection, analysis, and decontamination. The system is able to hold and access an unlimited number of fluorescent reagents that may be used to screen samples for the presence of specific sequences. The apparatus works by associating extracted and purified sample with a series of reagent plugs that have been formed in a flow channel and delivered to a flow-through real-time amplification detector that has a multiplicity of optical windows, to which the sample-reagent plugs are placed in an operative position. The diagnostic apparatus includes sample multi-position valves, a master sample multi-position valve, a master reagent multi-position valve, reagent multi-position valves, and an optical amplification/detection system.

Regan, John Frederick

2012-10-30T23:59:59.000Z

342

System and method for individually testing valves in a steam turbine trip control system  

SciTech Connect

This patent describes a steam turbine power plant. It comprises: a steam generator; a steam turbine adapted to receive steam form the steam generator; a throttle valve for regulating the flow of the steam received by the steam turbine; and an electro-hydraulic trip control system for causing the throttle valve to close when a predetermined condition has been reached.

Hurley, J.D.

1992-07-28T23:59:59.000Z

343

Wakefield induced Losses in the Manual Valves of the TESLA Cryomodule  

E-Print Network (OSTI)

1 Wakefield induced Losses in the Manual Valves of the TESLA Cryomodule M.Dohlus,H.-P.Wedekind,K.Zapfe DeutschesElektronenSynchrotron Notkestr.85,D-22603Hamburg,Germany Abstract The beam pipe of the TESLA valves with spring type rf-shield which are presently used in the linac of the TESLA Test Facility

344

KIVA-3V: A block-structured KIVA program for engines with vertical or canted valves  

DOE Green Energy (OSTI)

This report describes an extended version of KIVA-3, known as KIVA-3V, that can model any number of vertical or canted valves in the cylinder head of an internal combustion (IC) engine. The valves are treated as solid objects that move through the mesh using the familiar snapper technique used for piston motion in KIVA-3. Because the valve motion is modeled exactly, and the valve shapes are as exact as the grid resolution will allow, the accuracy of the valve model is commensurate with that of the rest of the program. Other new features in KIVA-3V include a particle-based liquid wall film model, a new sorting subroutine that is linear in the number of nodes and preserves the original storage sequence, a mixing-controlled turbulent combustion model, and an optional RNG {kappa}-{epsilon} turbulence model. All features and capabilities of the original KIVA-3 have been retained. The grid generator, K3PREP, has been expanded to support the generation of grids with valves, along with the shaping of valve ports and runners. Graphics output options have also been expanded. The report discusses the new features, and includes four examples of grids with vertical and canted valves that are representative of IC engines in use today.

Amsden, A.A.

1997-07-01T23:59:59.000Z

345

Proceedings of the 2nd symposium on valves for coal conversion and utilization  

SciTech Connect

The 2nd symposium on valves for coal conversion and utilization was held October 15 to 17, 1980. It was sponsored by the US Department of Energy, Morgantown Energy Technology Center, in cooperation with the Valve Manufacturers Association. Seventeen papers have been entered individually into EDB and ERA. (LTN)

Maxfield, D.A. (ed.)

1981-01-01T23:59:59.000Z

346

A New Operational Tests Circuit for Testing ±660kV UHVDC Thyristor Valves  

Science Conference Proceedings (OSTI)

Operational test is an important measure which can guarantee safe and stable operation of UHVDC thyristor valves. HVDC thyristor modules can be performed either in a six-pulse back-to-back test circuit or in a synthetic test circuit. UHVDC thyristor ... Keywords: HVDC thyristor valve, operational tests, synthetic test circuit

Ting Xie; Tang Guang-fu; Zha Kun-peng; Gao Chong

2010-06-01T23:59:59.000Z

347

Nuclear Maintenance Applications Center: Air-Operated Valve Diagnostic Testing Guide  

Science Conference Proceedings (OSTI)

This report provides information for personnel involved in the performance of air-operated valve (AOV) diagnostic testing, including the benefits of using diagnostics to understand valve health and to tie information into preventive maintenance programs. It provides insights for experienced personnel as well as basic information, guidance, and instructions for personnel assigned to perform, analyze, or purchase diagnostic test equipment.

2011-12-23T23:59:59.000Z

348

Fault Detection, Diagnosis and Prediction in Electrical Valves Using Self-Organizing Maps  

Science Conference Proceedings (OSTI)

This paper presents a proactive maintenance scheme for fault detection, diagnosis and prediction in electrical valves. The proposed scheme is validated with a case study, considering a specific valve used for controlling the oil flow in a distribution ... Keywords: Fault prediction, Proactive maintenance, Self-organizing maps, Test of electromechanical systems

Luiz Fernando Gonçalves; Jefferson Luiz Bosa; Tiago Roberto Balen; Marcelo Soares Lubaszewski; Eduardo Luis Schneider; Renato Ventura Henriques

2011-08-01T23:59:59.000Z

349

Endurance Tests of Valves With Cobalt-Free Hardfacing Alloys: PWR Phase Final Report  

Science Conference Proceedings (OSTI)

Gate valves hard-faced with three galling-resistant iron-base alloys and a cobalt-base standard were subjected to demanding cycling conditions in an environment simulating typical PWR primary chemistry conditions. Extensive nondestructive and destructive examinations showed that all valves with iron-base trim performed better than the cobalt-base standard after 1900 operating cycles.

1992-05-01T23:59:59.000Z

350

Optimal Scheduling of Cogeneration Plants  

E-Print Network (OSTI)

A cogeneration plant, feeding its output water into a district-heating grid, may include several types of energy producing units. The most important being the cogeneration unit, which produces both heat and electricity. Most plants also have a heat water storage. Finding the optimal production of both heat and electricity and the optimal use of the storage is a difficult optimization problem. This paper formulates a general approach for the mathematical modeling of a cogeneration plant. The model objective function is nonlinear, with nonlinear constraints. Internal plant temperatures, mass flows, storage losses, minimal up and down times and time depending start-up costs are considered. The unit commitment, i.e. the units on and off modes, is found with an algorithm based on Lagrangian relaxation. The dual search direction is given by the subgradient method and the step length by the Polyak rule II. The economic dispatch problem, i.e. the problem of determining the units production giv...

Erik Dotzauer; Kenneth Holmström

1997-01-01T23:59:59.000Z

351

Bacterial Foraging Optimization  

Science Conference Proceedings (OSTI)

The bacterial foraging optimization BFO algorithm mimics how bacteria forage over a landscape of nutrients to perform parallel nongradient optimization. In this article, the author provides a tutorial on BFO, including an overview of the biology of bacterial ... Keywords: Bacteria Foraging, Bacteria Foraging Optimization, Bacteria Motility, Control, Distributed Control, Optimization

Kevin M. Passino

2010-01-01T23:59:59.000Z

352

Why Pressure Reducing Valves (PVR's) are costing you money  

E-Print Network (OSTI)

Throughout many manufacturing facilities, colleges, commercial sites or industrial complexes, pressure reducing valves (PRV's) provide a cheap, reliable method to produce low pressure steam from a high pressure source in order to meet a process requirement or heating load. This simple method of expanding steam in a PRV creates no work and supplies the same heat content available in the high pressure steam at a more manageable low pressure. What if you could produce the same low pressure steam while saving hundreds of thousands of dollars on your electric bill and taking only a minimal hit in the available heat content? Why let steam down and get no benefit from it, when putting it through a low pressure steam turbine coupled to a generator would produce the heat you need for process with the byproduct of onsite electrical generation. This paper analyzes the costs, concerns and benefits of replacing a pressure reducing valve with a Steam Turbine Generator set including illustrations of what the marginal fuel increase would be in order to take advantage of the added benefits of clean, cheap and reliable onsite power production.

Downing, A.

2012-01-01T23:59:59.000Z

353

Fluid-driven reciprocating apparatus and valving for controlling same  

DOE Patents (OSTI)

A control valve assembly for alternately actuating a pair of fluid-driven free-piston devices by using fluid pressure communication therebetween. Each control valve is switched by a pressure signal depending on the state of its counterpart's piston. The communication logic is arranged to provide overlap of the forward strokes of the pistons, so that at least one of the pair will always be pressurized. Thus, uninterrupted pumping of liquid is made possible from a pair of free-piston pumps. In addition, the speed and frequency of piston stroking is entirely dependent on the mechanical power load applied. In the case of a pair of pumps, this enables liquid delivery at a substantially constant pressure over the full range of flow rates, from zero to maximum flow. One embodiment of the invention utilized two pairs of fluid-driven free-piston devices whereby a bipropellant liquid propulsion system may be operated, so as to provide continuous flow of both fuel and oxidizer liquids when used in rocket applications, for example.

Whitehead, John C. (Davis, CA); Toews, Hans G. (East Aurora, NY)

1993-01-01T23:59:59.000Z

354

Two-phase flow characteristics in multiple orifice valves  

SciTech Connect

This work presents an experimental investigation on the characteristics of two-phase flow through multiple orifice valve (MOV), including frictional pressure drop and void fraction. Experiments were carried out using an MOV with three different sets of discs with throat thickness-diameter ratios (s/d) of 1.41, 1.66 and 2.21. Tests were run with air and water flow rates ranging between 1.0 and 3.0 m{sup 3}/h, respectively. The two-phase flow patterns established for the experiment were bubbly and slug. Two-phase frictional multipliers, frictional pressure drop and void fraction were analyzed. The determined two-phase multipliers were compared against existing correlations for gas-liquid flows. None of the correlations tested proved capable of predicting the experimental results. The large discrepancy between predicted and measured values points at the role played by valve throat geometry and thickness-diameter ratio in the hydrodynamics of two-phase flow through MOVs. A modification to the constants in the two-phase multiplier equation used for pipe flow fitted the experimental data. A comparison between computed frictional pressure drop, calculated with the modified two-phase multiplier equation and measured pressure drop yielded better agreement, with less than 20% error. (author)

Alimonti, Claudio [Sapienza University of Rome, Department ICMA, Via Eudossiana 18, 00184 Roma (Italy); Falcone, Gioia; Bello, Oladele [The Harold Vance Department of Petroleum Engineering, Texas A and M University, 3116 TAMU, Richardson Building, College Station, TX 77843 (United States)

2010-11-15T23:59:59.000Z

355

Evaluation of wear resistant ceramic valve seats in gas-fueled power generation engines. Topical report, December 1991-April 1994  

SciTech Connect

This project is directed at the reduction of valve recession in natural gas-fueled engines. Ceramic valve seat inserts have been procured, installed in a Caterpillar G3516 natural gas generator set, and tested for 1000 hours. Two different silicon nitride materials are being utilized for the valve seats in addition to stock Eatonite metallic inserts. Three valve face materials are being tested. These include stock Caterpillar stellite 1 faced, stellite 6 faced, and unfaced valves. A test matrix was used to allow comparison of all three valve face materials in combination with all three insert materials. The testing is scheduled to continue for an additional 7000 hours. No problems have been encountered with the test materials. In general, it has been shown that two types of silicon nitride materials have at least short term durability in engine operation. Neither material has exhibited any deficiencies thus far. An economic analysis spreadsheet has been created to calculate potential cost savings potential using ceramic valve seat inserts. Valve recession data for the first 1000 hours shows expected trends. Exhaust valve positions are wearing more than intake valve positions. If the intake positions and all positions with unfaced valve are ignored, then ceramic inserts paired with Stellite 1 valves show the most wear.

Burrahm, R.W.; Branecky, R.J.; Sui, P.C.; Latusek, J.P.; Hsu, S.M.

1994-12-01T23:59:59.000Z

356

Optimization Online - Benchmark of Some Nonsmooth Optimization ...  

E-Print Network (OSTI)

Mar 1, 2006 ... Benchmark of Some Nonsmooth Optimization Solvers for Computing Nonconvex Proximal Points. Warren Hare (whare ***at*** cecm.sfu.ca)

357

Optimization Online - Nonlinear Optimization Submissions - 2013  

E-Print Network (OSTI)

Optimization of running strategies based on anaerobic energy and variations of velocity. Amandine Aftalion, J. Frédéric Bonnans. Convergence Analysis of DC ...

358

Optimization Online - Energy Security: a robust optimization ...  

E-Print Network (OSTI)

Sep 9, 2010 ... Energy Security: a robust optimization approach to design a robust European energy supply via TIAM. F Babonneau(fbabonneau ***at*** ...

359

Optimization Online - Python Optimization Modeling Objects (Pyomo)  

E-Print Network (OSTI)

Sep 24, 2008 ... sandia.gov). Abstract: We describe Pyomo, an open-source tool for modeling optimization applications in Python. Pyomo can be used to define ...

360

Optimization Online - Python Optimization Modeling Objects (Pyomo)  

E-Print Network (OSTI)

Dec 30, 2009 ... Python Optimization Modeling Objects (Pyomo). William Hart(wehart ***at*** sandia.gov) Jean-Paul Watson(jwatson ***at*** sandia.gov)

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Optimization Online - Projection methods in conic optimization  

E-Print Network (OSTI)

Mar 8, 2011 ... Citation: To appear as a contributed chapter of "Handbook of Semidefinite, Cone and Polynomial Optimization" edited by M. Anjos and J. B. ...

362

Optimization Online - Robust Optimization Submissions - 2012  

E-Print Network (OSTI)

An Exact Algorithm for Power Grid Interdiction Problem with Line Switching Long Zhao, Bo Zeng. An Exact Algorithm for Two-stage Robust Optimization with ...

363

Optimal estimation with limited measurements  

Science Conference Proceedings (OSTI)

This paper introduces a sequential estimation problem with two decision makers, or agents, who work as members of a team. One of the agents sits at an observation post, and makes sequential observations about the state of an underlying stochastic process ... Keywords: WSNs, limited information, networked control systems, optimal estimation, real-time control, real-time monitoring, recursive estimation, sequential estimation, wireless networks, wireless sensor networks

Orhan C. Imer; Tamer Basar

2010-01-01T23:59:59.000Z

364

Generic Optimization Program User Manual Version 3.0.0  

E-Print Network (OSTI)

Optimization Program User Manual Version 3.0.0 SimulationIt is clear that such a manual procedure is very time-optimization algorithm. This manual is structured as

Wetter, Michael

2009-01-01T23:59:59.000Z

365

Inverse Optimization: An Application to the Capacitated Plant Location Problem  

E-Print Network (OSTI)

Inverse optimization refers to the fact that each time a Lagrangean derived from a given mathematical programming problem is solved, it produces an optimal solution to some problem with a different right hand side. This ...

Bitran, Gabriel R.

366

The Dolph–Chebyshev Window: A Simple Optimal Filter  

Science Conference Proceedings (OSTI)

Analyzed data for numerical prediction can be effectively initialized by means of a digital filter. Computation time is reduced by using an optimal filter. The construction of optimal filters involves the solution of a nonlinear minimization ...

Peter Lynch

1997-04-01T23:59:59.000Z

367

Risk-Based Production Optimization  

Science Conference Proceedings (OSTI)

This report documents the pilot application of a risk-informed approach to production optimization at fossil power plants. In this project, EPRI worked with a U.S. utility to develop risk profiles for plant components at two of the utilitys coal-fired generating units. The information was then used as a basis for identifying timing strategies for performing outage-based maintenance. The primary objective was to apply a risk-informed approach to identifying an optimal sequence of outage intervals and scop...

2011-04-29T23:59:59.000Z

368

Optimal control, geometry, and quantum computing  

E-Print Network (OSTI)

We prove upper and lower bounds relating the quantum gate complexity of a unitary operation, U, to the optimal control cost associated to the synthesis of U. These bounds apply for any optimal control problem, and can be used to show that the quantum gate complexity is essentially equivalent to the optimal control cost for a wide range of problems, including time-optimal control and finding minimal distances on certain Riemannian, subriemannian, and Finslerian manifolds. These results generalize the results of Nielsen, Dowling, Gu, and Doherty, Science 311, 1133-1135 (2006), which showed that the gate complexity can be related to distances on a Riemannian manifold

Michael A. Nielsen; Mark R. Dowling; Mile Gu; Andrew C. Doherty

2006-03-19T23:59:59.000Z

369

Method of accounting for code safety valve setpoint drift in safety analyses  

Science Conference Proceedings (OSTI)

In performing the safety analyses for transients that result in a challenge to the reactor coolant system (RCS) pressure boundary, the general acceptance criterion is that the peak RCS pressure not exceed the American Society of Mechanical Engineers limit of 110% of the design pressure. Without crediting non-safety-grade pressure mitigating systems, protection from this limit is mainly provided by the primary and secondary code safety valves. In theory, the combination of relief capacity and setpoints for these valves is designed to provide this protection. Generally, banks of valves are set at varying setpoints staggered by 15- to 20-psid increments to minimize the number of valves that would open by an overpressure challenge. In practice, however, when these valves are removed and tested (typically during a refueling outage), setpoints are sometimes found to have drifted by >50 psid. This drift should be accounted for during the performance of the safety analysis. This paper describes analyses performed by Yankee Atomic Electric Company (YAEC) to account for setpoint drift in safety valves from testing. The results of these analyses are used to define safety valve operability or acceptance criteria.

Rousseau, K.R.; Bergeron, P.A.

1989-01-01T23:59:59.000Z

370

Optimal Foraging of Renewable Resources  

E-Print Network (OSTI)

Consider a team of agents in the plane searching for and visiting target points that appear in a bounded environment according to a stochastic renewal process with a known absolutely continuous spatial distribution. Agents must detect targets with limited-range onboard sensors. It is desired to minimize the expected waiting time between the appearance of a target point, and the instant it is visited. When the sensing radius is small, the system time is dominated by time spent searching, and it is shown that the optimal policy requires the agents to search a region at a relative frequency proportional to the square root of its renewal rate. On the other hand, when targets appear frequently, the system time is dominated by time spent servicing known targets, and it is shown that the optimal policy requires the agents to service a region at a relative frequency proportional to the cube root of its renewal rate. Furthermore, the presented algorithms in this case recover the optimal performance achieved by agents ...

Enright, John J

2011-01-01T23:59:59.000Z

371

Passively operated spool valve for drain-down freeze protection of thermosyphon water heaters. Final technical report  

SciTech Connect

The work done to extend the existing drain-down valve technology to provide passive drain-down freeze protection for thermosyphon-based solar water heaters is described. The basic design of the existing valve model is that of a spool valve, employing a cylindrical spool which moves axially in a mating cartridge to open and close o-rings at the two operating extremes (drain and operate) to perform the valving function. Three passive actuators to drive the basic valving mechanism were designed, fabricated, and tested. Two piping configurations used to integrate the spool valve with the thermosyphon system are described, as are the passive actuators. The three actuator designs are: photovoltaic driven, refrigerant-based bellows, and heat motor cable-drive designs. Costs are compared for the alternative actuator designs, and operating characteristics were examined for the thermosyphon system, including field tests. The market for the valve for thermosyphon systems is then assessed. (LEW)

1982-04-30T23:59:59.000Z

372

Electromagnetic valve for controlling the flow of molten, magnetic material  

DOE Patents (OSTI)

An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell.

Richter, Tomas (State College, PA)

1998-01-01T23:59:59.000Z

373

Electromagnetic valve for controlling the flow of molten, magnetic material  

DOE Patents (OSTI)

An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell. 5 figs.

Richter, T.

1998-06-16T23:59:59.000Z

374

Strength and fatigue of NT551 silicon nitride and NT551 diesel exhaust valves  

DOE Green Energy (OSTI)

The content of this report is excerpted from Mark Andrew's Ph.D. Thesis (Andrews, 1999), which was funded by a DOE/OTT High Temperature Materials Laboratory Graduate Fellowship. It involves the characterization of NT551 and valves fabricated with it. The motivations behind using silicon nitride (Si{sub 3}N{sub 4}) as an exhaust valve for a diesel engine are presented in this section. There are several economic factors that have encouraged the design and implementation of ceramic components for internal combustion (IC) engines. The reasons for selecting the diesel engine valve for this are also presented.

Andrews, M.J.; Werezczak, A.A.; Kirkland, T.P.; Breder, K.

2000-02-01T23:59:59.000Z

375

Proceedings of the symposium on inservice testing of pumps and valves  

Science Conference Proceedings (OSTI)

The 1990 Symposium on Inservice Testing of Pumps and Valves, jointly sponsored by the Board on Nuclear Codes and Standards of the American Society of Mechanical Engineers and by the Nuclear Regulatory Commission, provided a forum for the discussion of current programs and methods for inservice testing at nuclear power plants. The symposium also provided an opportunity to discuss the need to improve inservice testing in order to ensure the reliable performance of pumps and valves. The participation of industry representatives, regulators, and consultants resulted in the discussion of a broad spectrum of ideas and perspectives regarding the improvement of inservice testing of pumps and valves at nuclear power plants.

Not Available

1990-10-01T23:59:59.000Z

376

Endurance Tests of Valves With Cobalt-Free Hardfacing Alloys: BWR Phase Final Report  

Science Conference Proceedings (OSTI)

Valves hardfaced with three galling-resistant iron-base alloys (NOREM, EVERIT 50, and Deloro Stellite EB 5183) and a cobalt-base standard (Stellite 6) were subjected to stroke cycling in an environment simulating BWR chemistry conditions. Examination showed that the wear performance of valves with iron-base trim matched that of the cobalt-base standard. Yet, preferential corrosion of EB 5183 was found. Using cobalt-free alloys to replace or refurbish valves will significantly reduce released cobalt respo...

1993-03-01T23:59:59.000Z

377

Optimization of Cooling Water  

E-Print Network (OSTI)

A cooling water system can be optimized by operation at the highest possible cycles of concentration without risking sealing and fouling on heat exchanger surfaces. The way to optimize will be shown, with a number of examples of new systems.

Matson, J.

1985-05-01T23:59:59.000Z

378

Heterogeneous particle swarm optimizers  

Science Conference Proceedings (OSTI)

Particle swarm optimization (PSO) is a swarm intelligence technique originally inspired by models of flocking and of social influence that assumed homogeneous individuals. During its evolution to become a practical optimization tool, some heterogeneous ...

Marco A. Montes De Oca; Jorge Peña; Thomas Stützle; Carlo Pinciroli; Marco Dorigo

2009-05-01T23:59:59.000Z

379

Nonconvex robust optimization  

E-Print Network (OSTI)

We propose a novel robust optimization technique, which is applicable to nonconvex and simulation-based problems. Robust optimization finds decisions with the best worst-case performance under uncertainty. If constraints ...

Teo, Kwong Meng

2007-01-01T23:59:59.000Z

380

Erosion and Optimal Transport  

E-Print Network (OSTI)

383 pp. EROSION AND OPTIMAL TRANSPORT [23] I. Ekeland and T.and D. Simons, Sediment transport capacity of overland ?ow,measure spaces via optimal transport, Ann. of Math. (2),

Birnir, Bjorn; Rowlett, Julie

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

568.ps - Optimization Online  

E-Print Network (OSTI)

was implemented in the interactive system for universal functional optimization UFO. Results of extensive numerical experiments are reported. Keywords.

382

Optimal Control of the Solid Fuel Ignition Model with H1-Cost  

Science Conference Proceedings (OSTI)

Optimal control problems for the stationary as well as the time-dependent solid fuel ignition model are investigated. Existence of optimal controls is proved, and optimality systems are derived. The analysis is based on a closedness lemma for the exponential ... Keywords: control of exponential nonlinearity, explosion phenomena, optimal control, optimality conditions

Kazufumi Ito; Karl Kunisch

2001-05-01T23:59:59.000Z

383

Web based portfolio optimization  

Science Conference Proceedings (OSTI)

The portfolio optimization is implemented as e-service through Internet. Four-tier client-server model of WAN-based information system is designed satisfying the intersection of several domains: financial investments, optimization theory and information ... Keywords: portfolio optimization, system algorithmic architecture of information systems, web based information system

Todor Stoilov; Krasimira Stoilova

2009-06-01T23:59:59.000Z

384

Optimization Online - Optimizing Preventive Maintenance Models  

E-Print Network (OSTI)

Jun 29, 2004 ... Optimizing Preventive Maintenance Models ... It is assumed that there is a known model which predicts the frequency of system failure as a function of ... Category 2: Applications -- OR and Management Sciences (Scheduling ).

385

Particle Swarm Optimization Based Reactive Power Optimization  

E-Print Network (OSTI)

Reactive power plays an important role in supporting the real power transfer by maintaining voltage stability and system reliability. It is a critical element for a transmission operator to ensure the reliability of an electric system while minimizing the cost associated with it. The traditional objectives of reactive power dispatch are focused on the technical side of reactive support such as minimization of transmission losses. Reactive power cost compensation to a generator is based on the incurred cost of its reactive power contribution less the cost of its obligation to support the active power delivery. In this paper an efficient Particle Swarm Optimization (PSO) based reactive power optimization approach is presented. The optimal reactive power dispatch problem is a nonlinear optimization problem with several constraints. The objective of the proposed PSO is to minimize the total support cost from generators and reactive compensators. It is achieved by maintaining the whole system power loss as minimum...

Sujin, P R; Linda, M Mary

2010-01-01T23:59:59.000Z

386

Fail Save Shut Off Valve for Filtering Systems Employing Candle Filters  

NLE Websites -- All DOE Office Websites (Extended Search)

Fail Save Shut Off Fail Save Shut Off Valve for Filtering Systems Employing Candle Filters Opportunity The Department of Energy's National Energy Technology Laboratory (NETL) is seeking licensing partners interested in implementing United States Patent Number 6,981,516 entitled "Fail save shut off valve for filtering systems employing candle filters." Disclosed in this patent is a novel fail save shut off valve system that allows fluid flow during normal operational conditions, but prevents the flow of fluids in the event of system failure upstream that causes over- pressurization. It is particularly well suited for use in conjunction with hot gas filtering systems, which utilize ceramic candle filters. Used in such a hot gas system, the fail save valve stops the flow

387

Percutaneous aortic valve replacement in a re-animated postmortem heart  

E-Print Network (OSTI)

transcatheter implantation of heart valve prosthesis for thein apex of post-mortem heart (lower view). B C A Figure 5A.descending aorta in lambs. Eur Heart J. 2002;23:1045-49. 5.

White, Jennifer; Sun, Amy; Killien, Lauren; Evangelista, Dennis

2006-01-01T23:59:59.000Z

388

Dynamic simulation of heart mitral valve with transversely isotropic material model  

E-Print Network (OSTI)

This thesis develops two methods for simulating, in the finite element setting, the material behavior of heart mitral valve leaflet tissue. First, a mixed pressure-displacement formulation is used to implement the constitutive ...

Weinberg, Eli, 1979-

2005-01-01T23:59:59.000Z

389

Safety Evaluation Report, pump and valve inservice testing program, Maine Yankee Atomic Power Station  

Science Conference Proceedings (OSTI)

This EG and G, Inc., report presents the results of our evaluation of the Maine Yankee Atomic Power Station, Inservice Testing Program for pumps and valves whose function is important to safety.

Rockhold, H.C.; Stromberg, H.M.

1985-04-01T23:59:59.000Z

390

Electro-Hydraulic Servo-Valve and Motion and Control Loading of Full Flight Simulator.  

E-Print Network (OSTI)

??The present thesis is on the subject of electro-hydraulic servo-valve (EHV), and motion and control loading of a flight simulator with EHV. The fundamentals of… (more)

Shi, Wei

2010-01-01T23:59:59.000Z

391

DOE specification: Valve-regulated type lead-acid storage batteries  

DOE Green Energy (OSTI)

This document contains a ``fill-in-the-blanks`` guide specification for procurement of sealed valve-regulated type lead-acid storage batteries, for uninterruptible power supply applications.

NONE

1996-08-01T23:59:59.000Z

392

Template for Submission of Risk-Informed Inservice Testing Program for Pumps and Valves  

Science Conference Proceedings (OSTI)

Nuclear power plants must update their inservice testing program for pumps and valves to the latest ASME code every ten years. This report provides a template for requesting an alternative to the technical requirements contained in that code.

1998-09-17T23:59:59.000Z

393

Giant magnetoresistance in ion beam deposited spin-valve films with specular enhancement  

Science Conference Proceedings (OSTI)

Three different techniques, natural oxidation, remote plasma oxidation and low energy ion beam oxidation, have been proved to be equally effective in forming nano-oxide layers (NOLs) in spin-valve films for specular enhancement of giant magnetoresistance (GMR) effect. GMR values over 12% have been routinely obtained in spin-valve films with NOL, corresponding to a 30% specular enhancement over those without NOL. The consistency and robustness of the oxidation processes has been demonstrated by a very large GMR value {similar_to}19% in a dual spin-valve film with the NOLs formed in both pinned layers, the oscillatory dependence of the interlayer coupling field on Cu layer thickness in specular enhanced spin-valve films and the uniform and repeatable film performance over 5 in. substrates. {copyright} 2001 American Institute of Physics.

Sant, S.; Mao, M.; Kools, J.; Koi, K.; Iwasaki, H.; Sahashi, M.

2001-06-01T23:59:59.000Z

394

VALVE FUNNEL SPRING PIN PRESS PERFORMANCE AND FUNCTIONAL REQUIREMENTS EVALUATION FOR SPECIAL TOOLS AND EQUIPMENT  

SciTech Connect

This evaluation allows use of the valve funnel spring pin press and describes appropriate handling instructions for the tool. The engineering evaluation is required for operations and field use of special tools and equipment.

WITHERSPOON JT

2009-12-30T23:59:59.000Z

395

Granular Attrition due to Rotary Valve in a Pneumatic Conveying System  

E-Print Network (OSTI)

The rotary valve is a widely used mechanical device in many solids-handling industrial processes. However, it may also be responsible for most of the attrition effects occurring in a typical process. In this study, the ...

Yao, Jun

396

Method and apparatus utilizing valve throttling and charge stratification in the operation of an internal combustion engine  

Science Conference Proceedings (OSTI)

In an internal combustion engine this patent describes means forming a combustion chamber, a spark plug in the chamber, a piston disposed in the chamber for reciprocable movement toward and away from the spark plug, a valve member, circular seat means for the valve member, means for varying the lift of the valve member, a generally cylindrical shroud corresponding generally to the size of the seat means. The cylindrical shroud is relieved only in the direction of the spark plug so that, when the valve member is moved relative to the shroud by the lift-varying means, a stratified mixture of air and fuel is directed toward the spark plug until the lift-varying means causes the valve member to pass beyond the shroud so that during the initial lift of the valve member the stratified air and fuel mixture is directed solely toward the spark plug until the valve member passes beyond the shroud and the air and fuel mixture is directed generally through a 360/sup 0/ arc after the valve member passes beyond the shroud, and means limiting the lift of the valve member so that it does not pass the shroud during lighter loads, whereby the air and fuel mixture is directed primarily toward the spark plug until the valve member passes beyond the shroud.

Burandt, C.O.

1988-02-16T23:59:59.000Z

397

Nanostructured Coatings for Improved Erosion Resistance of Valve Stem Materials – 2013 Field Test Trials Update  

Science Conference Proceedings (OSTI)

The Electric Power Research Institute- (EPRI-) developed nanostructured coatings (nanocoatings), deposited by plasma- enhanced magnetron sputtering, show great promise for improved erosion and wear resistance in many power plant applications. EPRI laboratory research in 2010 developed the processing to apply these coatings over nitrided/malcomized (hardened) steam turbine valve stems, which is described in EPRI report 1019796, Application of Nanocoatings for Erosion Protection of Valve ...

2013-12-20T23:59:59.000Z

398

AECL Qualification of Greases for Motor-Operated Valve Stem/Stem Nut Lubrication  

Science Conference Proceedings (OSTI)

The frictional characteristics of lubricants used in the actuators of motor-operated valves are critical to ensuring adequate actuator output capability. As part of the EPRI Motor-Operated Valve (MOV) Performance Prediction Program, testing was conducted at ambient temperature conditions on over 20 stem-stem nut lubricants in use in United States nuclear plants as documented in EPRI report TR-103235. Additional research has been conducted on several MOV lubricants after thermal and radiation aging under ...

1998-11-24T23:59:59.000Z

399

A Hamilton-Jacobi-Bellman approach to optimal trade execution  

Science Conference Proceedings (OSTI)

The optimal trade execution problem is formulated in terms of a mean-variance tradeoff, as seen at the initial time. The mean-variance problem can be embedded in a linear-quadratic (LQ) optimal stochastic control problem. A semi-Lagrangian scheme is ... Keywords: HJB equation, Mean-variance tradeoff, Optimal execution, Semi-Lagrangian discretization, Viscosity solution

Peter A. Forsyth

2011-02-01T23:59:59.000Z

400

Optimal fault location  

E-Print Network (OSTI)

Basic goal of power system is to continuously provide electrical energy to the users. Like with any other system, failures in power system can occur. In those situations it is critical that correct remedial actions are applied as soon as possible after the accurate fault condition and location are detected. This thesis has been focusing on automated fault location procedure. Different fault location algorithms, classified according to the spatial placement of physical measurements on single ended, multiple ended and sparse system-wide, are investigated. As outcome of this review, methods are listed as function of different parameters that influence their accuracy. This comparison is than used for generating procedure for optimal fault location algorithm selection. According to available data, and position of the fault with respect to the data, proposed procedure decides between different algorithms and selects an optimal one. A new approach is developed by utilizing different data structures such as binary tree and serialization in order to efficiently implement algorithm decision engine. After accuracy of algorithms is strongly influenced by available input data, different data sources are recommended in proposed architecture such as the digital fault recorders, circuit breaker monitoring, SCADA, power system model and etc. Algorithm for determining faulted section is proposed based on the data from circuit breaker monitoring devices. This algorithm works in real time by recognizing to which sequence of events newly obtained recording belongs. Software prototype of the proposed automated fault location analysis is developed using Java programming language. Fault location analysis is automatically triggered by appearance of new event files in a specific folder. The tests were carried out using the real life transmission system as an example.

Knezev, Maja

2007-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Pareto-optimal glowworm swarms optimization for smart grids management  

Science Conference Proceedings (OSTI)

This paper presents a novel nature-inspired multi-objective optimization algorithm. The method extends the glowworm swarm particles optimization algorithm with algorithmical enhancements which allow to identify optimal pareto front in the objectives ... Keywords: evolutionary optimization, micro-grids, pareto optimization, swarm-optimization

Eleonora Riva Sanseverino; Maria Luisa Di Silvestre; Roberto Gallea

2013-04-01T23:59:59.000Z

402

An acceleration procedure for optimal first-order methods  

E-Print Network (OSTI)

Jul 17, 2012 ... As compared with standard optimal first-order methods, our schemes allows us to divide computation times by two to three orders of magnitude ...

403

Optimal Stopping with Information Constraint  

SciTech Connect

We study the optimal stopping problem proposed by Dupuis and Wang (Adv. Appl. Probab. 34:141-157, 2002). In this maximization problem of the expected present value of the exercise payoff, the underlying dynamics follow a linear diffusion. The decision maker is not allowed to stop at any time she chooses but rather on the jump times of an independent Poisson process. Dupuis and Wang (Adv. Appl. Probab. 34:141-157, 2002), solve this problem in the case where the underlying is a geometric Brownian motion and the payoff function is of American call option type. In the current study, we propose a mild set of conditions (covering the setup of Dupuis and Wang in Adv. Appl. Probab. 34:141-157, 2002) on both the underlying and the payoff and build and use a Markovian apparatus based on the Bellman principle of optimality to solve the problem under these conditions. We also discuss the interpretation of this model as optimal timing of an irreversible investment decision under an exogenous information constraint.

Lempa, Jukka, E-mail: jlempa@cma.uio.no [University of Oslo, Centre of Mathematics for Applications (Norway)

2012-10-15T23:59:59.000Z

404

Optimization as a Driver for Design Space Exploration  

E-Print Network (OSTI)

This paper describes an approach toward the use of optimization which is a departure from the traditional role optimization plays in the design process. Traditionally, optimization is used to improve point solutions in the latter phases of design. In this work, optimization is used as an aid for design space exploration, through the integration of optimization and iterative design. Two applications of the concept of optimization-driven design are given: CAD tools for HVAC layout and an assembly design framework. 1 INTRODUCTION The use of optimization in design is becoming increasingly prevalent in industry today. This is due to a variety of factors, including a marketplace that imposes greater competitive pressures to produce higher-quality products at lower costs while reducing product development times, as well as more powerful computer hardware and new optimization techniques, both of which allow the application of optimization to problems where it was not previously possible. Whi...

Simon Szykman Manufacturing; Simon Szykman

1997-01-01T23:59:59.000Z

405

Optimization Online Digest -- July 2003  

E-Print Network (OSTI)

Mathematical optimization for the inverse problem of intensity modulated ... The global optimization of Morse clusters by potential energy transformations

406

Optimization Online Digest -- February 2013  

E-Print Network (OSTI)

Extension of Completely Positive Cone Relaxation to Polynomial Optimization ... Optimal Power Grid Protection through A Defender-Attacker-Defender Model

407

Optimization Online Digest -- February 2011  

E-Print Network (OSTI)

... Optimization for Power System Configuration with Renewable Energy in Remote Areas ... Robust Energy Cost Optimization of Water Distribution System with ...

408

Optimization Online Digest -- November 2004  

E-Print Network (OSTI)

Friedrich Eisenbrand, Gianpaolo Oriolo, Gautier Stauffer, Paolo Ventura. Convex and Nonsmooth Optimization Finding optimal algorithmic parameters using a ...

409

Energy optimization system  

DOE Patents (OSTI)

A system for optimizing customer utility usage in a utility network of customer sites, each having one or more utility devices, where customer site is communicated between each of the customer sites and an optimization server having software for optimizing customer utility usage over one or more networks, including private and public networks. A customer site model for each of the customer sites is generated based upon the customer site information, and the customer utility usage is optimized based upon the customer site information and the customer site model. The optimization server can be hosted by an external source or within the customer site. In addition, the optimization processing can be partitioned between the customer site and an external source.

Zhou, Zhi; de Bedout, Juan Manuel; Kern, John Michael; Biyik, Emrah; Chandra, Ramu Sharat

2013-01-22T23:59:59.000Z

410

Optimized Constant Pressure Stochastic Dynamics  

E-Print Network (OSTI)

A recently proposed method for computer simulations in the isothermal-isobaric (NPT) ensemble, based on Langevin-type equations of motion for the particle coordinates and the ``piston'' degree of freedom, is re-derived by straightforward application of the standard Kramers-Moyal formalism. An integration scheme is developed which reduces to a time-reversible symplectic integrator in the limit of vanishing friction. This algorithm is hence expected to be quite stable for small friction, allowing for a large time step. We discuss the optimal choice of parameters, and present some numerical test results.

A. Kolb; B. Duenweg

1999-03-29T23:59:59.000Z

411

Optimized constant pressure stochastic dynamics  

E-Print Network (OSTI)

A recently proposed method for computer simulations in the isothermal– isobaric (NPT) ensemble, based on Langevin–type equations of motion for the particle coordinates and the “piston ” degree of freedom, is re–derived by straightforward application of the standard Kramers–Moyal formalism. An integration scheme is developed which reduces to a time–reversible symplectic integrator in the limit of vanishing friction. This algorithm is hence expected to be quite stable for small friction, allowing for a large time step. We discuss the optimal choice of parameters, and present some numerical test results.

A. Kolb; B. Dünweg

1999-01-01T23:59:59.000Z

412

Cooling Plant Optimization Guide  

Science Conference Proceedings (OSTI)

Central cooling plants or district cooling systems account for 22 percent of energy costs for cooling commercial buildings. Improving the efficiency of central cooling plants will significantly impact peak demand and energy usage for both building owners and utilities. This guide identifies opportunities for optimizing a central cooling plant and provides a simplified optimization procedure. The guide focuses on plant optimization from the standpoint of minimizing energy costs and maximizing efficiencies...

1998-09-29T23:59:59.000Z

413

Optimization Online - Test  

E-Print Network (OSTI)

Jan 25, 2006 ... Test. Andrew Goldberg (goldberg ***at*** cs.wisc.edu). Abstract: Test. Keywords: Test. Category 1: Infinite Dimensional Optimization ...

414

Nonlinear Optimization Test  

E-Print Network (OSTI)

Jun 8, 2000 ... Nonlinear Optimization Test Goux Jean-Pierre Abstract : this is my abstract. Keywords : this are keywords. Citation: : this is a citation. Download ...

415

Postscript - Optimization Online  

E-Print Network (OSTI)

design of an industrial electric motor. This allows to show that ...... We consider the optimal design of Interior Permanent Magnet (IPM) syn-. chronous motors [19

416

Distributionally Robust Convex Optimization  

E-Print Network (OSTI)

function of the respective optimization problem, and the upper curve reports the out-of-sample results from a .... Duxbury Thomson Learning, 2nd edition, 2002.

417

Homotopy optimization methods for global optimization.  

SciTech Connect

We define a new method for global optimization, the Homotopy Optimization Method (HOM). This method differs from previous homotopy and continuation methods in that its aim is to find a minimizer for each of a set of values of the homotopy parameter, rather than to follow a path of minimizers. We define a second method, called HOPE, by allowing HOM to follow an ensemble of points obtained by perturbation of previous ones. We relate this new method to standard methods such as simulated annealing and show under what circumstances it is superior. We present results of extensive numerical experiments demonstrating performance of HOM and HOPE.

Dunlavy, Daniel M.; O'Leary, Dianne P. (University of Maryland, College Park, MD)

2005-12-01T23:59:59.000Z

418

Nuclear Maintenance Applications Center: Application Guide for Motor-Operated Valves in Nuclear Power Plants - Revision 2  

Science Conference Proceedings (OSTI)

Motor-operated gate and globe valves are widely used in both safety-related and non-safety-related systems in nuclear power plants. Their proper operation is essential for reliable plant performance and can help eliminate costly downtime. This second revision of the Application Guide for Motor-Operated Valves provides the latest in methods for conducting engineering evaluations in order to confirm that motor-operated gate, globe, and butterfly valves will perform their required function and offers sugges...

2007-08-22T23:59:59.000Z

419

Acceptance test report for the AN valve pit leak detection and low point drain assembly mock up test procedure  

SciTech Connect

This document describes The Performance Mock-up Test Procedure for the Valve Pit Leak Detection and Low Point Drain Assembly Performance Mock-Up Test Procedure.

EWER, K.L.

1999-07-20T23:59:59.000Z

420

Modulation Optimization under Energy Constraints  

E-Print Network (OSTI)

We consider radio applications where the nodes operate on batteries so that energy consumption must be minimized while satisfying given throughput and delay requirements. In this context, we analyze the best modulation strategy to minimize the total energy consumption required to send a given number of bits. The total energy consumption includes both the transmission energy and the circuit energy consumption. We show that for both MQAM and MFSK the transmission energy decreases with the product while the circuit energy consumption increases with , where is the modulation bandwidth and the transmission time. Thus, in short-range applications where the circuit energy consumption is nonnegligible compared with the transmission energy, the total energy consumption is minimized by using the maximum system bandwidth along with an optimized transmission time . We derive this optimal for MQAM and MFSK modulation in both AWGN channels and Rayleigh fading channels. Our optimization considers both delay and peak-power constraints. Numerical examples are given, where we exhibit up to 2 energy savings over modulation strategies that minimize the transmission energy alone.

Shuguang Cui Andrea; Andrea J. Goldsmith; Ahmad Bahai

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Optimal Source Tracking and Beaming of LISA  

E-Print Network (OSTI)

We revisit the directionally optimal data streams of LISA first introduced in Nayak etal. It was shown that by using appropriate choice of Time delay interferometric (TDI) combinations, a monochromatic fixed source in the barycentric frame can be optimally tracked in the LISA frame. In this work, we study the beaming properties of these optimal streams. We show that all the three streams V+, Vx and Vo with maximum, minimum and zero directional SNR respectively are highly beamed. We study in detail the frequency dependence of the beaming.

Archana Pai

2006-08-31T23:59:59.000Z

422

Voltage Control Optimization to Improve Transmission Efficiency  

Science Conference Proceedings (OSTI)

An optimal power flow solution is unique from a conventional power flow solution in that an objective function and user-specified constraints are enforced and satisfied to reach a valid solution. This report presents an analytical study on the optimization of power flow in order to minimize reactive power losses via the modification of generator voltage schedules and transmission switched shunt status. The study examines the potential benefits and applicability of near-real-time voltage control ...

2012-11-08T23:59:59.000Z

423

Optimizing Capital Investment Decisions at Intel Corporation  

Science Conference Proceedings (OSTI)

Intel Corporation spends over $5 billion annually on manufacturing equipment. With increasing lead times from equipment suppliers and increasing complexity in forecasting market demand, optimizing capital investment decisions is a significant ... Keywords: Monte Carlo simulation, capacity expansion, capital-intensive industries, dual sourcing, expedited equipment lead times, forecast revision, isoprofit analysis, option contracts, stochastic programming

Karl G. Kempf; Feryal Erhun; Erik F. Hertzler; Timothy R. Rosenberg; Chen Peng

2013-01-01T23:59:59.000Z

424

Integrated Energy System Dispatch Optimization  

DOE Green Energy (OSTI)

On-site cogeneration of heat and electricity, thermal and electrical storage, and curtailing/rescheduling demand options are often cost-effective to commercial and industrial sites. This collection of equipment and responsive consumption can be viewed as an integrated energy system(IES). The IES can best meet the sites cost or environmental objectives when controlled in a coordinated manner. However, continuously determining this optimal IES dispatch is beyond the expectations for operators of smaller systems. A new algorithm is proposed in this paper to approximately solve the real-time dispatch optimization problem for a generic IES containing an on-site cogeneration system subject to random outages, limited curtailment opportunities, an intermittent renewable electricity source, and thermal storage. An example demonstrates how this algorithm can be used in simulation to estimate the value of IES components.

Firestone, Ryan; Stadler, Michael; Marnay, Chris

2006-06-16T23:59:59.000Z

425

Effects of boron composition on tunneling magnetoresistance ratio and microstructure of CoFeB/MgO/CoFeB pseudo-spin-valve magnetic tunnel junctions  

SciTech Connect

The effect of B concentration on the tunneling magnetoresistance (TMR) of (Co{sub 25}Fe{sub 75}){sub 100-x}B{sub x}/MgO/(Co{sub 25}Fe{sub 75}){sub 100-x}B{sub x} (x = 22 and 33) pseudo-spin-valve (P-SV) magnetic tunnel junctions (MTJs) was investigated. The TMR ratios for optimally annealed MTJs with x = 22 and 33 were 340% and 170%, respectively, at room temperature. High resolution transmission electron microscopy (HRTEM) observation showed a weaker (001) texture in the MgO barrier in the MTJ with x = 33. The bottom electrode was not fully crystallized even with a considerable amount of B in the (Co{sub 25}Fe{sub 75}){sub 67}B{sub 33}, while good epitaxy was observed between (001) textured MgO and (Co{sub 25}Fe{sub 75}){sub 78}B{sub 22} electrodes.

Kodzuka, M. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-0047 (Japan); Ohkubo, T. [National Institute for Materials Science, Tsukuba 305-0047 (Japan); Hono, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-0047 (Japan); National Institute for Materials Science, Tsukuba 305-0047 (Japan); Ikeda, S.; Ohno, H. [Center for Spintronics Integrated Systems, Tohoku University, Sendai 980-8577 (Japan); Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577 (Japan); Gan, H. D. [Center for Spintronics Integrated Systems, Tohoku University, Sendai 980-8577 (Japan)

2012-02-15T23:59:59.000Z

426

Heart valve cardiomyocytes of mouse embryos express the serotonin transporter SERT  

SciTech Connect

Multiple evidence demonstrate a role for serotonin and its transporter SERT in heart valve development and disease. By utilizing a Cre/loxP system driven by SERT gene expression, we recently demonstrated a regionally restricted distribution of SERT-expressing cells in developing mouse heart. In order to characterize the cell types exhibiting SERT expression within the mouse heart valves at early developmental stages, in this study we performed immunohistochemistry for Islet1 (Isl1) and connexin-43 (Cx-43) on heart sections from SERT{sup Cre/+};ROSA26R embryos previously stained with X-gal. We observed the co-localization of LacZ staining with Isl1 labelling in the outflow tract, the right ventricle and the conal region of E11.5 mouse heart. Cx-43 labelled cells co-localized with LacZ stained cells in the forming atrioventricular valves. These results demonstrate the cardiomyocyte phenotype of SERT-expressing cells in heart valves of the developing mouse heart, thus suggesting an active role of SERT in early heart valve development.

Pavone, Luigi Michele [Department of Biological Structures, Functions and Technologies, University of Naples Federico II, Via F. Delpino 1, 80137 Naples (Italy); Department of Biochemistry and Medical Biotechnologies, University of Naples Federico II, Naples (Italy)], E-mail: pavone@dbbm.unina.it; Spina, Anna; Lo Muto, Roberta; Santoro, Dionea [Department of Biological Structures, Functions and Technologies, University of Naples Federico II, Via F. Delpino 1, 80137 Naples (Italy); Department of Biochemistry and Medical Biotechnologies, University of Naples Federico II, Naples (Italy); Mastellone, Vincenzo [Department of Experimental Medicine 'G. Salvatore', University of Magna Graecia, Catanzaro (Italy); Avallone, Luigi [Department of Biological Structures, Functions and Technologies, University of Naples Federico II, Via F. Delpino 1, 80137 Naples (Italy)

2008-12-12T23:59:59.000Z

427

Uncertainty Analysis for a Virtual Flow Meter Using an Air-Handling Unit Chilled Water Valve  

SciTech Connect

A virtual water flow meter is developed that uses the chilled water control valve on an air-handling unit as a measurement device. The flow rate of water through the valve is calculated using the differential pressure across the valve and its associated coil, the valve command, and an empirically determined valve characteristic curve. Thus, the probability of error in the measurements is significantly greater than for conventionally manufactured flow meters. In this paper, mathematical models are developed and used to conduct uncertainty analysis for the virtual flow meter, and the results from the virtual meter are compared to measurements made with an ultrasonic flow meter. Theoretical uncertainty analysis shows that the total uncertainty in flow rates from the virtual flow meter is 1.46% with 95% confidence; comparison of virtual flow meter results with measurements from an ultrasonic flow meter yielded anuncertainty of 1.46% with 99% confidence. The comparable results from the theoretical uncertainty analysis and empirical comparison with the ultrasonic flow meter corroborate each other, and tend to validate the approach to computationally estimating uncertainty for virtual sensors introduced in this study.

Song, Li; Wang, Gang; Brambley, Michael R.

2013-04-28T23:59:59.000Z

428

Apparatus and method for non-invasive diagnosis and control of motor operated valve condition  

DOE Patents (OSTI)

An apparatus compares the torque from an MOV motor with the valve displacement, and from the comparison assesses MOV operating condition. A transducer measures the vibration of the housing of an MOV. The vibrations are due to the motions of the rotating elements within the housing, which motions are directly related to the motion of the valve relative to its seat. Signal processing apparatus analyzes the vibrations to recover the rotations of the rotating elements and thus the motion of the valve plug. Lost motion can also be determined (if a lost motion connection exists) by demodulating the vibration signal and thus taking into account also the lost motion. Simultaneously, the forces applied to the valve are estimated by estimating the torque between the stator and the rotor of the motor. Such torque can be estimated from measuring the input current and voltage alone, using a forgetting factor and a correction for the forgetting factor. A signature derived from relating the torque to the valve position can be used to assess the condition of the MOV, by comparing the signature to signatures for MOVs of known conditions. The vibration analysis components generate signals that relate to the position of elements in the operator. Similarly, the torque estimator estimates the torque output by any type of electric motor, whether or not part of an MOV analysis unit. 28 figs.

Lyon, R.H.; Chai, J.; Lang, J.H.; Hagman, W.H.; Umans, S.D.; Saarela, O.J.

1997-01-14T23:59:59.000Z

429

English-Spanish glossary: offshore exploration and production, gas processing, and valves  

Science Conference Proceedings (OSTI)

This series of articles contains 3 different English-Spanish glossaries of related terms used in the oil industry. The glossary of the offshore exploration and production involves a summary of terms used in the offshore oil activity. It also includes names of singular equipment used in offshore drilling, as well as several navigation terms in relation to the floating oil structures. With the help of the Gas Processors Association it was possible to compile a glossary of gas processing with a concise selection of common terms of the industry of gas processing. The glossary of valves includes more than 200 terms of the industry of valves in a specialized glossary, and several explanations about the application and operation of valves.

Not Available

1981-12-01T23:59:59.000Z

430

Failure analyses of two ball valves used for coal-gasification applications  

SciTech Connect

Two ball valves which had failed by developing excess leakage were supplied for analyses. The 2'' (51 mm) valve had experienced 5000 cycles during 20 hrs usage in an unknown chemical environment. Wear on the ball and seats was a multi-stage process starting with breakdown of a hard chrome plating on the stainless steel ball. This eventually led to adhesive weld transfer of the stainless steel to the seat made of Stellite 6 alloy. The 6'' (152 mm) ball valve had experienced a cycling test sequence using compressed air up to 300 psig (2.07 MPa) at 850/sup 0/F (727/sup 0/K). Damage was characterized as abrasive wear caused either by particles deposited by the compressed air or by carbide particles present in the Stellite 6 alloy ball and seat hardfacing. The decrease in this alloy's compressive yield strength at the elevated test temperature contributed to increased wear rates.

Van Den Avyle, J.A.; Pope, L.E.

1982-07-01T23:59:59.000Z

431

Model test optimization using the virtual environment for test optimization  

SciTech Connect

We present a software environment integrating analysis and test-based models to support optimal modal test design through a Virtual Environment for Test Optimization (VETO). The VETO assists analysis and test engineers to maximize the value of each modal test. It is particularly advantageous for structural dynamics model reconciliation applications. The VETO enables an engineer to interact with a finite element model of a test object to optimally place sensors and exciters and to investigate the selection of data acquisition parameters needed to conduct a complete modal survey. Additionally, the user can evaluate the use of different types of instrumentation such as filters, amplifiers and transducers for which models are available in the VETO. The dynamic response of most of the virtual instruments (including the device under test) are modeled in the state space domain. Design of modal excitation levels and appropriate test instrumentation are facilitated by the VETO`s ability to simulate such features as unmeasured external inputs, A/D quantization effects, and electronic noise. Measures of the quality of the experimental design, including the Modal Assurance Criterion, and the Normal Mode Indicator Function are available. The VETO also integrates tools such as Effective Independence and minamac to assist in selection of optimal sensor locations. The software is designed about three distinct modules: (1) a main controller and GUI written in C++, (2) a visualization model, taken from FEAVR, running under AVS, and (3) a state space model and time integration module built in SIMULINK. These modules are designed to run as separate processes on interconnected machines.

Klenke, S.E.; Reese, G.M.; Schoof, L.A.; Shierling, C.

1995-11-01T23:59:59.000Z

432

Definition: Real-Time Load Transfer | Open Energy Information  

Open Energy Info (EERE)

Real-time load transfer is achieved through real-time feeder reconfiguration and optimization to relieve load on equipment, improve asset utilization, improve distribution...

433

Optimization Online - Optimal Job Scheduling with Day-ahead Price ...  

E-Print Network (OSTI)

Aug 17, 2011 ... Optimization Online. Optimal Job Scheduling with Day-ahead Price and Random Local Distributed Generation: A Two-stage Robust Approach.

434

Toward self-optimization of machine intelligence  

SciTech Connect

For a long time there has been interest in putting a computer program that solves problems to work on the problem of optimizing its own abilities, though little has been done to formally realize this ambition. This work offers a mathematical theory of computerized problem solving. Under the theory a problem solver, represented as a computer program, is able to rigorously consider the problem of optimizing its own ability to solve problems, or in some sense, its intelligence. The notions of problem and of what it means to solve it had to be broadened considerably beyond their usual meanings. In the resulting theory of limiting optimization a binary preference relation or ordering is assigned to a class of objects. The problem then becomes one of constructing an optimizing sequnce of objects that tend to an optimal conditions that, under the preference relation, only a finite number of terms of the sequence can be equivalent or inferior to any given, suboptimal object. The theory is able to handle the more conventional versions of problem solving such as theorem proving as well as esoteric forms of optimization in the limit. It is possible to define an IQ test for a problem solver or organism that solves limiting optimization problems.

Perry, R.M.

1984-01-01T23:59:59.000Z

435

Whitey Swagelok SCHe ball valves Provide Isolation between SCHe Purge Lines C and D and the Process Vent  

Science Conference Proceedings (OSTI)

These valves are 1/4 inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They provide an isolation function betwen SCHe Purge Line C, (PV-V-*079), and Purge Line D, (PV-V-*080), and the Process Vent.

MISKA, C.R.

2000-09-03T23:59:59.000Z

436

Energy-Saving Control of Single-Rod Hydraulic Cylinders with Programmable Valves and Improved Working Mode Selection  

E-Print Network (OSTI)

tremendous flexibility to control the cylinder motion while decreasing the energy usage by utilizing and individual cylinder chamber pressure control for better energy saving. With a typical four-way directional energy usage. The programmable valve configuration used in this study is seen in Figure 1. Cylinder Valve

Yao, Bin

437

Review article: A review of particle swarm optimization and its applications in Solar Photovoltaic system  

Science Conference Proceedings (OSTI)

Particle swarm optimization is a stochastic optimization, evolutionary and simulating algorithm derived from human behaviour and animal behaviour as well. Special property of particle swarm optimization is that it can be operated in continuous real number ... Keywords: Linearly decreasing inertia weight, PSO parameters & control, Particle swarm optimization, Solar Photovoltaics, Time varying acceleration coefficients

Anula Khare; Saroj Rangnekar

2013-05-01T23:59:59.000Z

438

Optimized Maintenance of Generator Rotors  

Science Conference Proceedings (OSTI)

Generator rotor maintenance options are limited and expensive. The timing and scope of work done requires optimization to obtain the maximum benefits for continued long-term trouble-free operation. This document is a comprehensive guide to the maintenance of large generator rotors of 2 and 4 pole design that are cooled directly or indirectly by air or hydrogen. These include 50 and 60 Hz machines, operating at speeds of 1500, 1800, 3000, and 3600 RPM. The guide does not cover water-cooled rotors. The inf...

2004-12-13T23:59:59.000Z

439

Risk and robust optimization  

E-Print Network (OSTI)

This thesis develops and explores the connections between risk theory and robust optimization. Specifically, we show that there is a one-to-one correspondence between a class of risk measures known as coherent risk measures ...

Brown, David Benjamin, Ph. D. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

440

Polyethylene fiber drawing optimization  

E-Print Network (OSTI)

Polymer fiber drawing creates fibers with enhanced thermal conductivity and strength compared to bulk polymer because drawing aligns the molecular chains. I optimize the polymer fiber drawing method in order to achieve ...

Chiloyan, Vazrik

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Optimizing workflow data footprint  

Science Conference Proceedings (OSTI)

In this paper we examine the issue of optimizing disk usage and scheduling large-scale scientific workflows onto distributed resources where the workflows are data-intensive, requiring large amounts of data storage, and the resources have limited storage ...

Gurmeet Singh; Karan Vahi; Arun Ramakrishnan; Gaurang Mehta; Ewa Deelman; Henan Zhao; Rizos Sakellariou; Kent Blackburn; Duncan Brown; Stephen Fairhurst; David Meyers; G. Bruce Berriman; John Good; Daniel S. Katz

2007-12-01T23:59:59.000Z

442

Optimal transport strategies  

E-Print Network (OSTI)

It is generally presupposed that the shapes and mechanisms encountered in nature have evolved in such a way as to maximize the robustness of a species. However, most such optimization problems arising in biology are ...

Kim, Wonjung, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

443

Optimal distance separating halfspace  

E-Print Network (OSTI)

Plastria & Carrizosa / Optimal distance separating halfspace. 2. 1 Gauge Distance to a Hyperplane. Let ? be a gauge on Rd with unit ball B, i.e. B is a compact ...

444

Optimization of Hot Standby  

E-Print Network (OSTI)

Energy Optimization is one of the key issues facing the chemical process industries today. The drivers are both economic and environmental. Utilities are among the top operating expenses for manufacturers, reflecting elevated energy prices and the energy

de Souza, J.; Holden, D.

2004-01-01T23:59:59.000Z

445

1052.ps - Optimization Online  

E-Print Network (OSTI)

a natural approach of formulating problems where it is necessary to simultaneously. optimize the system ... deign of gas or water transmission networks. ..... region of the linear programming relaxation is compressed because of the decrease.

446

1093.ps - Optimization Online  

E-Print Network (OSTI)

The Semidefinite Program (SDP) is a fundamental problem in mathematical .... SDPs arising from quantum chemistry [11, 24] and polynomial optimization [17, 19], ...... R. Saigal and L. Vandenberghe, Handbook of Semidefinite Programming ,.

447

View - Optimization Online  

E-Print Network (OSTI)

accuracy and v(xk) is not sufficiently small, or if the new constraint violation satisfies ...... RRR 12-94, Rutgers University, New Brunswick, NJ, USA. ... Nonlinear Optimization, Technical Report, Rutherford Appleton Laboratory, Chilton, Ox-.

448

Optimal Parametric Auctions  

E-Print Network (OSTI)

We study the problem of profit maximization in auctions of one good where the buyers' valuations are drawn from independent distributions. When these distributions are known to the seller, Myerson's optimal auction is a ...

Azar, Pablo

2012-05-08T23:59:59.000Z

449

Fail Save Shut Off Valve for Filtering Systems Employing Candle Filters  

DOE Patents (OSTI)

The invention relates to an apparatus that acts as a fail save shut off valve. More specifically, the invention relates to a fail save shut off valve that allows fluid flow during normal operational conditions, but prevents the flow of fluids in the event of system failure upstream that causes over-pressurization. The present invention is particularly well suited for use in conjunction with hot gas filtering systems, which utilize ceramic candle filters. Used in such a hot gas system the present invention stops the flow of hot gas and prevents any particulate laden gas from entering the clean side of the system.

VanOsdol, John

2006-01-03T23:59:59.000Z

450

Optimization Online Digest -- January 2001  

E-Print Network (OSTI)

E. Alper Yildirim, Michael J. Todd. Network Optimization Newton Algorithms for Large-Scale Strictly Convex Separable Network Optimization Aleksandar Donev  ...

451

Optimization of Lithium Titanate Electrodes  

NLE Websites -- All DOE Office Websites (Extended Search)

Optimization of Lithium Titanate Electrodes Title Optimization of Lithium Titanate Electrodes Publication Type Journal Article Year of Publication 2006 Authors Christensen, John,...

452

Mixed-Integer Nonlinear Optimization  

E-Print Network (OSTI)

Nov 22, 2012 ... Our goal is to find the minimum cost design by choosing optimal ..... et al., 1998), the optimal response to catastrophic oil spills such as the ...

453

Optimization Online Digest -- January 2013  

E-Print Network (OSTI)

Optimization Online Digest — January 2013. Applications — OR and Management Sciences A two-step optimization approach for job shop scheduling problem ...

454

Optimization strategies for discrete multi-material stiffness optimization  

Science Conference Proceedings (OSTI)

Design of composite laminated lay-ups are formulated as discrete multi-material selection problems. The design problem can be modeled as a non-convex mixed-integer optimization problem. Such problems are in general only solvable to global optimality ... Keywords: Integer optimization, Laminated composite materials, Optimal design, Sensitivity analysis, Solution strategies

Christian Frier Hvejsel; Erik Lund; Mathias Stolpe

2011-08-01T23:59:59.000Z

455

Time-Constrained Loop Pipelining  

Science Conference Proceedings (OSTI)

This paper addresses the problem of Time-Constrained Loop Pipelining, i.e. given a fixed throughput, finding a schedule of a loop which minimizes resource requirements. This paper proposes a methodology, called TCLP, based on dividing the problem into ... Keywords: loop pipelining, scheduling, timing and resource contraints, register optimization

Fermin Sanchez

1995-12-01T23:59:59.000Z

456

Numerical analysis of the heat transfer for packing design of cryogenic gate valve  

Science Conference Proceedings (OSTI)

The packing, among the components comprising the gate valve, is used to sustain the airtightness and the study on change of shape or pattern has been carried out to maximize the functions, but the study on changing the location or the size of the packing ... Keywords: cryogenic, heat transfer, liquefied natural gas, numerical analysis, packing

Si Pom Kim; Rock Won Jeon; Il Ju Hwang; Jae Hoon Lee; Won Heaop Shin

2012-04-01T23:59:59.000Z

457

Analysis on Modulation Principle of Mechanical Spring Valve Block-Type Pulse Jet  

Science Conference Proceedings (OSTI)

To take full advantage of the bottom-hole hydraulic energy to improve the drilling rate, it is proposed the technique assumption that using mechanical spring valve periodically is to block the fluid pathway, and modulating pulse jet is to increase the ... Keywords: block type, pulse jet, drilling rate, water hammer, experimental study

Ni Hongjian; Zhu Lihong; Huo Hongjun; Tang Zhiwen

2011-08-01T23:59:59.000Z

458

New electromagnetic methods for the evaluation of prosthetic heart valves (invited)  

Science Conference Proceedings (OSTI)

Prosthetic devices are being implanted at record levels as the nation “ages” and advances in prosthetic science are made. Devices that are implanted range from artificial limbs and hips to devices such as heart valves. Periodic evaluation of the state of the devices is of significant interest particularly in the case of prosthetics whose failure can be fatal. An example of such a device is the artificial heart valve. Heart valves are usually replaced when stenosis or incompetence is indicated. This article presents a selection of some new techniques that are being developed for the detection of outlet strut failures in Bjork-Shiley heart valves. Methods that show particular promise include a noninvasive electromagnetic method that relies on the excitation and measurement of the resonant vibration modes of the strut. An alternate approach involves the induction of currents in the outlet strut using a pair of external excitation coils. The field generated by the current induced in the strut perturbs the field generated by the excitation coils. The field perturbations are measured using a catheter-mounted gradiometer. Test results obtained using an experimental rig designed to demonstrate the proof-of-concept are presented.

Satish Udpa

2002-01-01T23:59:59.000Z

459

Mathematical Modeling of Current-Interrupt and Pulse Operation of Valve-Regulated Lead Acid Cells  

E-Print Network (OSTI)

are resolved. Of the two candidate battery systems, the low cost and ease of operation of the VRLA battery the last decade, advanced batteries have re- ceived much attention. At present, only the valve-regulated lead acid VRLA and the nickel-metal hydride Ni-MH battery are being actively considered

460

A valve with seat?slope proportional to flow area at all poppet positions  

Science Conference Proceedings (OSTI)

An adjustable gas?blending apparatus is hypothesized that would maintain a consistent mixture over a broad range of flowrates. The design equations for the unique valve seat required for such an apparatus are developed and solved numerically. An example seat is calculated and illustrated in table form. For preliminary study

D. W. Guillaume; D. DeVries

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Strength and Fatigue of NT551 Silicon Nitride and NT551 Diesel Exhaust Valves  

DOE Green Energy (OSTI)

The content of this report is excerpted from Mark Andrew's Ph.D. Thesis (Andrews, 1999), which was funded by a DOEYOTT High Temperature Materials Laboratory Graduate Fellowship. It involves the characterization of NT551 and valves fabricated with it. Greater detail of the described issues may be found in that reference or through communications with Andrew Wereszczak.

Andrews, M.J.; Wereszczak, A.A.; Kirkland, T.P.; Breder, K.

2000-02-01T23:59:59.000Z

462

Endurance tests of valves with cobalt-free hardfacing alloys: PWR phase  

SciTech Connect

Atomic Energy of Canada Limited (AECL) is conducting endurance tests on valves hard-faced with four cobalt-free alloys. The first phase of the program, in which PWR primary heat transport conditions were simulated in AECL's valve test loop, has been completed. The candidate alloys are NOREM 01, NOREM 04, EB 5183 and EVERIT 50. One valve with Stellite 6 trim served as the standard. Prior to loop testing, a baseline inaugural inspection was performed. During testing the loop was shutdown at approximately 500 cycle intervals, and the valves were disassembled for examination. The examinations included seat leak tests, profilometry, nondestructive inspection and finally destructive examination. Corrosion coupons in the loop were used to monitor any material loss due solely to corrosion mechanisms. This report summarizes the final examination results and discusses the relative performance of the candidate alloys. The results indicate that, based upon the sliding wear damage assessment and seat leakage test results, all the candidate alloys perform better than the Stellite 6 control sample. On the same basis, NOREM 04 and EB 5183 are the best of the candidate alloys, although there are only minor differences in performance among the four alloys.

Murphy, E.V.; Inglis, I. (Atomic Energy of Canada Ltd., Mississauga, ON (Canada))

1992-05-01T23:59:59.000Z

463

Temperature impacts on the set pressure of soft seated pressure relief valves  

SciTech Connect

From a safety standpoint, regardless of plant or facility type, the most important pieces of equipment are the pressure relief devices. The most critical characteristics of a pressure relief device are its set pressure and the related relieving capacity. The Set Pressure of a pressure relief device is defined as that value of increasing inlet static pressure at which the discharge becomes continuous (ASME PTC 25-1994, Performance Test Codes). To preclude an unsafe overpressure situation, the set pressure of the pressure relief device must not exceed the maximum allowable working pressure of the equipment or system being protected. Because of testing facility limitations, size or pressure, pressure relief valves intended for elevated temperature service are often set using ambient temperature air. Adjustments are made to the ambient valve opening pressures to compensate for the temperature differences. The extent of the adjustments to the pressure relief valve set pressure is important to ensure the valve will provide the required overpressure protection at the elevated in-service temperature.

Engel, J.J.; Zirps, G.T.; Gleason, R.B. [and others

1995-11-01T23:59:59.000Z

464

Condition monitoring of motor-operated valves in nuclear power plants Pierre Granjon  

E-Print Network (OSTI)

to the valve and increases radiation exposure of operators, leading to long overhaul outage and high techniques rely on the measurement of an internal mechanical quantity and require the presence of human of any internal MOV quantity. In this article, the instantaneous active power absorbed by the induction

Paris-Sud XI, Université de

465

Technical Repair Guidelines for Limitorque Models SMB 0 Through 4 Valve Actuators  

Science Conference Proceedings (OSTI)

This technical repair guide for Limitorque motor-operated valve (MOV) actuator models SMB 0 through 4 represents the third in a series of documents devoted to the comprehensive maintenance and repair of Limitorque actuators. This guide provides instructions for engineering, operations, and maintenance personnel on MOV actuator repair, maintenance, adjustment, and troubleshooting methods.

1993-02-28T23:59:59.000Z

466

Lattice Boltzmann Simulation Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

Boltzmann Boltzmann Simulation Optimization on Leading Multicore Platforms Selected as Best Paper in Application Track, IPDPS 2008, April 14-28, Miami, Florida, USA Samuel Williams † , Jonathan Carter , Leonid Oliker John Shalf , Katherine Yelick † CRD/NERSC, Lawrence Berkeley National Laboratory Berkeley, CA 94720 † CS Division, University of California at Berkeley, Berkeley, CA 94720 {SWWilliams, JTCarter, LOliker, JShalf, KAYelick}@lbl.gov Abstract We present an auto-tuning approach to optimize ap- plication performance on emerging multicore architec- tures. The methodology extends the idea of search- based performance optimizations, popular in linear al- gebra and FFT libraries, to application-specific com- putational kernels. Our work applies this strategy to a lattice Boltzmann application (LBMHD) that histor- ically has made poor use of scalar microprocessors

467

Hopper Performance and Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

Optimization Optimization Performance and Optimization Compiler Comparisons Comparison of different compilers with different options on several benchmarks. Read More » Using OpenMP Effectively Performance implications and case studies of codes combining MPI and OpenMP Read More » Reordering MPI Ranks Reordering MPI ranks can result in improved application performance depending on the communication patterns of the application. Read More » Application Performance Variability on Hopper How an application is placed across Hopper's roughly 6300 compute nodes can affect its performance. See a study of application runtimes vs node placement. Read More » Hopper Performance Monitoring Benchmarking performance of scientific applications on Hopper Read More » Hopper:Improving I/O performance to GSCRATCH and PROJECT

468

Reverse Osmosis Optimization  

SciTech Connect

This technology evaluation was prepared by Pacific Northwest National Laboratory on behalf of the U.S. Department of Energy’s Federal Energy Management Program (FEMP). ¬The technology evaluation assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. This evaluation provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption. The evaluation is intended to help facility managers at Federal sites understand the basic concepts of the RO process and system optimization options, enabling them to make informed decisions during the system design process for either new projects or recommissioning of existing equipment. This evaluation is focused on commercial-sized RO systems generally treating more than 80 gallons per hour.¬

McMordie-Stoughton, Katherine L.; Duan, Xiaoli; Wendel, Emily M.

2013-08-26T23:59:59.000Z

469

A characterization of check valve degradation and failure experience in the nuclear power industry: 1984-1990. Volume 1  

SciTech Connect

Check valve operating problems in recent years have resulted in significant operating transients, increased cost and decreased system availability. As a result, additional attention has beau given to check valves by utilities (resulting in the formation of the Nuclear Industry Check Valve Group), as well as the US Nuclear Regulatory Commission and the American Society of Mechanical Engineers Operation and Maintenance Committee. All these organizations have the fundamental goal of ensuring reliable operation of check valves. A key ingredient to an engineering-oriented reliability improvement effort is a thorough understanding of relevant historical experience. A detailed review of historical failure data, available through the Institute of Nuclear Power Operation`s Nuclear Plant Reliability Data System, has been conducted. The focus of the review is on check valve failures that have involved significant degradation of the valve internal parts. A variety of parameters are considered, including size, age, system of service, method of failure discovery, the affected valve parts, attributed causes, and corrective actions.

Casada, D.A.; Todd, M.D. [Oak Ridge National Lab., TN (United States)] [Oak Ridge National Lab., TN (United States)

1993-09-01T23:59:59.000Z

470

Optimal statistical model for forecasting ozone  

Science Conference Proceedings (OSTI)

The objective of this paper is to apply time series analysis and multiple regression method to ozone data in order to obtain the optimal statistical model for forecasting next day ozone level. The best estimated model is then used to produce one-step ... Keywords: ARMA (p, q), Durbin-Watson Statistic, MAPE, R-square, multiple regression

M. Abdollahian; R. Foroughi; N. Debnath

2006-04-01T23:59:59.000Z

471

Optimal operation and design of solar-thermal energy storage systems  

E-Print Network (OSTI)

The present thesis focuses on the optimal operation and design of solar-thermal energy storage systems. First, optimization of time-variable operation to maximize revenue through selling and purchasing electricity to/from ...

Lizarraga-García, Enrique

2012-01-01T23:59:59.000Z

472

Holistic ship design optimization  

Science Conference Proceedings (OSTI)

Ship design is a complex endeavor requiring the successful coordination of many disciplines, of both technical and non-technical nature, and of individual experts to arrive at valuable design solutions. Inherently coupled with the design process is design ... Keywords: Enhanced survivability, Genetic algorithms, Holistic ship design, Minimization of resistance and wash, Multi-objective optimization

Apostolos Papanikolaou

2010-11-01T23:59:59.000Z

473

933.ps - Optimization Online  

E-Print Network (OSTI)

Aug 30, 2004 ... optimization problem on a ner grid (see Griewank and Toint, 1982, Banks, Gill and .... clear that n is typically large, since it usually grows as some power of the ...... extensions to be possible and the resulting algorithms to be of ...

474

Cooling Water System Optimization  

E-Print Network (OSTI)

During summer months, many manufacturing plants have to cut back in rates because the cooling water system is not providing sufficient cooling to support higher production rates. There are many low/no-cost techniques available to improve tower performance. To understand the importance of the optimization techniques, cooling tower theory will be discussed first.

Aegerter, R.

2005-01-01T23:59:59.000Z

475

Optimization in Mung Chiang  

E-Print Network (OSTI)

Optimization in Networking Mung Chiang Princeton University 10th MOPTA August 18, 2010 #12;Routing variables {xl, s} #12;Power Control P. Hande,S. Rangan, M. Chiang, X. Wu, "Distributed uplink power control. Chen, S. Liu, S. Sengputa, M. Chiang, J. Li, and P. A. Chou, "P2P streaming capacity", IEEE

Chiang, Mung

476

Optimal Energy Management Policies for Energy Harvesting Sensor Nodes  

E-Print Network (OSTI)

1 Optimal Energy Management Policies for Energy Harvesting Sensor Nodes Vinod Sharma, Senior Member the energy available at that time. We obtain energy management policies that are throughput optimal, i.e., the data queue stays stable for the largest possible data rate. Next we obtain energy management policies

Sharma, Vinod

477

A survey of methods for gas-lift optimization  

Science Conference Proceedings (OSTI)

This paper presents a survey of methods and techniques developed for the solution of the continuous gas-lift optimization problem over the last two decades. These range from isolated single-well analysis all the way to real-time multivariate optimization ...

Kashif Rashid, William Bailey, Benoît Couët

2012-01-01T23:59:59.000Z

478

Optimal control of batteries with fully and partially available rechargeability  

Science Conference Proceedings (OSTI)

Motivated by the increasing dependence of many systems on battery energy, we study the problem of optimally controlling how to discharge and recharge a non-ideal battery so as to maximize the work it can perform over a given time period and still maintain ... Keywords: Energy-aware system, Kinetic battery model, Optimal control

Tao Wang; Christos G. Cassandras

2012-08-01T23:59:59.000Z

479

A hybrid real-parameter genetic algorithm for function optimization  

Science Conference Proceedings (OSTI)

One drawback of genetic algorithm is that it may spend much computation time in the encoding and decoding processes. Also, since genetic algorithm lacks hill-climbing capacity, it may easily fall in a trap and find a local minimum not the true solution. ... Keywords: Adaptive mechanism, Design optimization, Function optimization, Genetic algorithm, Simulated annealing

Shun-Fa Hwang; Rong-Song He

2006-01-01T23:59:59.000Z

480

An ant algorithm for optimization of hole-making operations  

Science Conference Proceedings (OSTI)

This paper deals with the optimization of hole-making operations in conditions where a hole may need several tools to get completed. The objective of interest in the considered problem is to minimize the summation of tool airtime and tool switch time. ... Keywords: Ant algorithms, Drilling, Hole-making, Optimization

Heidar Ghaiebi; Maghsud Solimanpur

2007-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Optimal control of generator resynchronisation in electric power systems  

Science Conference Proceedings (OSTI)

Optimal control techniques are discussed for the resynchronisation of a steam turbine unit in an electric power system after it has lost synchronism. A time optimal control is derived and the resulting bang-bang control law is first simulated on an analogue ...

D. Rosenfeld; F. J. Evans

1972-11-01T23:59:59.000Z

482

A parallel hybrid optimization algorithm for fitting interatomic potentials  

Science Conference Proceedings (OSTI)

In this work we present the parallel implementation of a hybrid global optimization algorithm assembled specifically to tackle a class of time consuming interatomic potential fitting problems. The resulting objective function is characterized by large ... Keywords: Cluster programming, Hybrid global optimization, Interatomic potential, Irregular task parallelism, Multidimensional search, Particle swarm

C. Voglis, P. E. Hadjidoukas, D. G. Papageorgiou, I. E. Lagaris

2013-12-01T23:59:59.000Z

483

Simulation-based optimal Bayesian experimental design for nonlinear systems  

Science Conference Proceedings (OSTI)

The optimal selection of experimental conditions is essential to maximizing the value of data for inference and prediction, particularly in situations where experiments are time-consuming and expensive to conduct. We propose a general mathematical framework ... Keywords: Bayesian inference, Chemical kinetics, Nonlinear experimental design, Optimal experimental design, Shannon information, Stochastic approximation, Uncertainty quantification

Xun Huan; Youssef M. Marzouk

2013-01-01T23:59:59.000Z

484

Optimal generation of entanglement under local control  

E-Print Network (OSTI)

We study the optimal generation of entanglement between two qubits subject to local unitary control. With the only assumptions of linear control and unitary dynamics, by means of a numerical protocol based on the variational approach (Pontryagin's Minimum Principle), we evaluate the optimal control strategy leading to the maximal achievable entanglement in an arbitrary interaction time, taking into account the energy cost associated to the controls. In our model we can arbitrarily choose the relative weight between a large entanglement and a small energy cost.

Raffaele Romano; Alessio Del Fabbro

2007-07-11T23:59:59.000Z

485

Optimal generation of entanglement under local control  

E-Print Network (OSTI)

We study the optimal generation of entanglement between two qubits subject to local unitary control. With the only assumptions of linear control and unitary dynamics, by means of a numerical protocol based on the variational approach (Pontryagin's Minimum Principle), we evaluate the optimal control strategy leading to the maximal achievable entanglement in an arbitrary interaction time, taking into account the energy cost associated to the controls. In our model we can arbitrarily choose the relative weight between a large entanglement and a small energy cost.

Romano, Raffaele

2007-01-01T23:59:59.000Z

486

In-Cylinder Reaction Chemistry and Kinetics During Negative Valve Overlap Fuel Injection Under Low-Oxygen Conditions  

DOE Green Energy (OSTI)

Fuel injection into the negative valve overlap (NVO) period is a common method for controlling combustion phasing in homogeneous charge compression ignition (HCCI) as well as other forms of advanced combustion. During this event, at least a portion of the fuel hydrocarbons can be converted to products containing significant levels of H2 and CO, as well as other short chain hydrocarbons by means of thermal cracking, water-gas shift, and partial oxidation reactions, depending on the availability of oxygen and the time-temperature-pressure history. The resulting products alter the autoignition properties of the combined fuel mixture for HCCI. Fuel-rich chemistry in a partial oxidation environment is also relevant to other high efficiency engine concepts (e.g., the dedicated EGR (D-EGR) concept from SWRI). In this study, we used a unique 6-stroke engine cycle to experimentally investigate the chemistry of a range of fuels injected during NVO under low oxygen conditions. Fuels investigated included iso-octane, iso-butanol, ethanol, and methanol. Products from NVO chemistry were highly dependent on fuel type and injection timing, with iso-octane producing less than 1.5% hydrogen and methanol producing more than 8%. We compare the experimental trends with CHEMKIN (single zone, 0-D model) predictions using multiple kinetic mechanisms available in the current literature. Our primary conclusion is that the kinetic mechanisms investigated are unable to accurately predict the magnitude and trends of major species we observed.

Kalaskar, Vickey B [ORNL] [ORNL; Szybist, James P [ORNL] [ORNL; Splitter, Derek A [ORNL] [ORNL; Pihl, Josh A [ORNL] [ORNL; Gao, Zhiming [ORNL] [ORNL; Daw, C Stuart [ORNL] [ORNL

2013-01-01T23:59:59.000Z

487